scsi: qla2xxx: Complain if a mailbox command times out

This patch fixes the following Coverity complaint:

Unchecked return value (CHECKED_RETURN)
check_return: Calling wait_for_completion_timeout without checking return
value (as is done elsewhere 14 out of 17 times).

Cc: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_mr.c

@@ -148,7 +148,8 @@ qlafx00_mailbox_command(scsi_qla_host_t *vha, struct mbx_cmd_32 *mcp)
 		QLAFX00_SET_HST_INTR(ha, ha->mbx_intr_code);
 		spin_unlock_irqrestore(&ha->hardware_lock, flags);
 
-		wait_for_completion_timeout(&ha->mbx_intr_comp, mcp->tov * HZ);
+		WARN_ON_ONCE(wait_for_completion_timeout(&ha->mbx_intr_comp,
+							 mcp->tov * HZ) != 0);
 	} else {
 		ql_dbg(ql_dbg_mbx, vha, 0x112c,
 		    "Cmd=%x Polling Mode.\n", command);