nvmet: avoid dereferencing nvmet_req

No need to dereference req twice to get the cmd when we already
have it stored in a local variable.

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/target/fabrics-cmd.c

@@ -220,7 +220,7 @@ int nvmet_parse_connect_cmd(struct nvmet_req *req)
 
 	req->ns = NULL;
 
-	if (req->cmd->common.opcode != nvme_fabrics_command) {
+	if (cmd->common.opcode != nvme_fabrics_command) {
 		pr_err("invalid command 0x%x on unconnected queue.\n",
 			cmd->fabrics.opcode);
 		return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;