scsi: qedf: Add missing return in qedf_post_io_req() in the fcport offload check

Fixes the following crash as the return was missing from the check if an
fcport is offloaded. If we hit this code we continue to try to post an
invalid task which can lead to the crash:

[30259.616411] [0000:61:00.3]:[qedf_post_io_req:989]:3: Session not offloaded yet.
[30259.616413] [0000:61:00.3]:[qedf_upload_connection:1340]:3: Uploading connection port_id=490020.
[30259.623769] BUG: unable to handle kernel NULL pointer dereference at 0000000000000198
[30259.631645] IP: [<ffffffffc035b1ed>] qedf_init_task.isra.16+0x3d/0x450 [qedf]
[30259.638816] PGD 0
[30259.640841] Oops: 0000 [#1] SMP
[30259.644098] Modules linked in: fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables devlink ip6table_filter ip6_tables iptable_filter vfat fat ib_isert iscsi_target_mod ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_ucm ib_umad dm_service_time skx_edac intel_powerclamp coretemp intel_rapl iosf_mbi kvm_intel kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel rpcrdma sunrpc rdma_ucm ib_uverbs lrw gf128mul ib_iser rdma_cm iw_cm ib_cm libiscsi scsi_transport_iscsi qedr(OE) glue_helper ablk_helper cryptd ib_core dm_round_robin joydev pcspkr ipmi_ssif ses enclosure ipmi_si ipmi_devintf ipmi_msghandler mei_me
[30259.715529]  mei sg hpilo hpwdt shpchp wmi lpc_ich acpi_power_meter dm_multipath ip_tables xfs libcrc32c sd_mod crc_t10dif crct10dif_generic uas usb_storage mgag200 qedf(OE) i2c_algo_bit libfcoe drm_kms_helper libfc syscopyarea sysfillrect scsi_transport_fc qede(OE) sysimgblt fb_sys_fops ptp ttm pps_core drm qed(OE) smartpqi crct10dif_pclmul crct10dif_common crc32c_intel i2c_core scsi_transport_sas scsi_tgt dm_mirror dm_region_hash dm_log dm_mod
[30259.754237] CPU: 9 PID: 977 Comm: kdmwork-253:7 Kdump: loaded Tainted: G        W  OE  ------------   3.10.0-862.el7.x86_64 #1
[30259.765664] Hardware name: HPE Synergy 480 Gen10/Synergy 480 Gen10 Compute Module, BIOS I42 04/04/2018
[30259.775000] task: ffff8c801efd0000 ti: ffff8c801efd8000 task.ti: ffff8c801efd8000
[30259.782505] RIP: 0010:[<ffffffffc035b1ed>]  [<ffffffffc035b1ed>] qedf_init_task.isra.16+0x3d/0x450 [qedf]
[30259.792116] RSP: 0018:ffff8c801efdbbb0  EFLAGS: 00010046
[30259.797444] RAX: 0000000000000000 RBX: ffffa7f1450948d8 RCX: ffff8c7fe5bc40c8
[30259.804600] RDX: ffff8c800715b300 RSI: ffffa7f1450948d8 RDI: ffff8c80169c2480
[30259.811755] RBP: ffff8c801efdbc30 R08: 00000000000000ae R09: ffff8c800a314540
[30259.818911] R10: ffff8c7fe5bc40c8 R11: ffff8c801efdb8ae R12: 0000000000000000
[30259.826068] R13: ffff8c800715b300 R14: ffff8c80169c2480 R15: ffff8c8005da28e0
[30259.833223] FS:  0000000000000000(0000) GS:ffff8c803f840000(0000) knlGS:0000000000000000
[30259.841338] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[30259.847100] CR2: 0000000000000198 CR3: 000000081242e000 CR4: 00000000007607e0
[30259.854256] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[30259.861412] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[30259.868568] PKRU: 00000000
[30259.871278] Call Trace:
[30259.873737]  [<ffffffffc035c948>] qedf_post_io_req+0x148/0x680 [qedf]
[30259.880201]  [<ffffffffc035d070>] qedf_queuecommand+0x1f0/0x240 [qedf]
[30259.886749]  [<ffffffffa329b050>] scsi_dispatch_cmd+0xb0/0x240
[30259.892600]  [<ffffffffa32a45bc>] scsi_request_fn+0x4cc/0x680
[30259.898364]  [<ffffffffa3118ad9>] __blk_run_queue+0x39/0x50
[30259.903954]  [<ffffffffa3114393>] __elv_add_request+0xd3/0x260
[30259.909805]  [<ffffffffa311baf0>] blk_insert_cloned_request+0xf0/0x1b0
[30259.916358]  [<ffffffffc010b622>] map_request+0x142/0x220 [dm_mod]
[30259.922560]  [<ffffffffc010b716>] map_tio_request+0x16/0x40 [dm_mod]
[30259.928932]  [<ffffffffa2ebb1f5>] kthread_worker_fn+0x85/0x180
[30259.934782]  [<ffffffffa2ebb170>] ? kthread_stop+0xf0/0xf0
[30259.940284]  [<ffffffffa2ebae31>] kthread+0xd1/0xe0
[30259.945176]  [<ffffffffa2ebad60>] ? insert_kthread_work+0x40/0x40
[30259.951290]  [<ffffffffa351f61d>] ret_from_fork_nospec_begin+0x7/0x21
[30259.957750]  [<ffffffffa2ebad60>] ? insert_kthread_work+0x40/0x40
[30259.963860] Code: fe 41 55 49 89 d5 41 54 53 48 89 f3 48 83 ec 58 4c 8b 67 28 4c 8b 4e 18 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 4c 8b 7e 58 <49> 8b 84 24 98 01 00 00 48 8b 00 f6 80 31 01 00 00 10 0f 85 0b
[30259.983372] RIP  [<ffffffffc035b1ed>] qedf_init_task.isra.16+0x3d/0x450 [qedf]
[30259.990630]  RSP <ffff8c801efdbbb0>
[30259.994127] CR2: 0000000000000198
Signed-off-by: Chad Dupuis <cdupuis@marvell.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qedf/qedf_io.c

@@ -902,6 +902,7 @@ int qedf_post_io_req(struct qedf_rport *fcport, struct qedf_ioreq *io_req)
 	if (!test_bit(QEDF_RPORT_SESSION_READY, &fcport->flags)) {
 		QEDF_ERR(&(qedf->dbg_ctx), "Session not offloaded yet.\n");
 		kref_put(&io_req->refcount, qedf_release_cmd);
+		return -EINVAL;
 	}
 
 	/* Obtain free SQE */