nvmet-tcp: fix possible memory leak

when we uninit a command in error flow we also need to
free an iovec if it was allocated.

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 0d63f3d..76e4375 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1309,6 +1309,7 @@ static void nvmet_tcp_finish_cmd(struct nvmet_tcp_cmd *cmd)
 {
 	nvmet_req_uninit(&cmd->req);
 	nvmet_tcp_unmap_pdu_iovec(cmd);
+	kfree(cmd->iov);
 	if (cmd->req.sg_cnt)
 		sgl_free(cmd->req.sg);
 }