nvmet-auth: clean up with done_kfree

Jump directly to done_kfree to release d, which is consistent with the
code style behind.
Reported-by: Genjian Zhang <zhanggenjian@kylinos.cn>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/target/fabrics-cmd-auth.c

@@ -229,10 +229,8 @@ void nvmet_execute_auth_send(struct nvmet_req *req)
 	}
 
 	status = nvmet_copy_from_sgl(req, 0, d, tl);
-	if (status) {
-		kfree(d);
-		goto done;
-	}
+	if (status)
+		goto done_kfree;
 
 	data = d;
 	pr_debug("%s: ctrl %d qid %d type %d id %d step %x\n", __func__,