IB/hfi1: Remove unreachable code

Remove unreachable code from RC ack handling to fix an
smatch error.

Fixes: 633d2739 ("staging/rdma/hfi1: use mod_timer when appropriate")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/rc.c

@@ -1497,7 +1497,7 @@ static int do_rc_ack(struct rvt_qp *qp, u32 aeth, u32 psn, int opcode,
 		/* Ignore reserved NAK codes. */
 		goto bail_stop;
 	}
-	return ret;
+	/* cannot be reached  */
 bail_stop:
 	hfi1_stop_rc_timers(qp);
 	return ret;