scsi: csiostor: Remove set but not used variable 'pln'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/csiostor/csio_attr.c: In function 'csio_fcoe_free_vnp':
drivers/scsi/csiostor/csio_attr.c:500:21: warning:
 variable 'pln' set but not used [-Wunused-but-set-variable]
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/csiostor/csio_attr.c

@@ -497,7 +497,6 @@ csio_fcoe_alloc_vnp(struct csio_hw *hw, struct csio_lnode *ln)
 static int
 csio_fcoe_free_vnp(struct csio_hw *hw, struct csio_lnode *ln)
 {
-	struct csio_lnode *pln;
 	struct csio_mb  *mbp;
 	struct fw_fcoe_vnp_cmd *rsp;
 	int ret = 0;
@@ -514,8 +513,6 @@ csio_fcoe_free_vnp(struct csio_hw *hw, struct csio_lnode *ln)
 		goto out;
 	}
 
-	pln = ln->pln;
-
 	csio_fcoe_vnp_free_init_mb(ln, mbp, CSIO_MB_DEFAULT_TMO,
 				   ln->fcf_flowid, ln->vnp_flowid,
 				   NULL);