IB/hfi1: Don't call cond_resched in atomic mode when sending packets

This patch fixed the problem where the driver might reschedule in atomic
mode when sending packets. This is due to the fact that the call to
cond_resched() in hfi1_do_send() might occur in atomic mode and a check is
required to avoid the warning message:
    "kernel: BUG: scheduling while atomic: swapper/2/0/0x10000100."
Reviewed-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NKaike Wan <kaike.wan@intel.com>
Signed-off-by: NJubin John <jubin.john@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/ruc.c

@@ -906,8 +906,11 @@ void hfi1_do_send(struct rvt_qp *qp)
 						*ps.ppd->dd->send_schedule);
 					return;
 				}
-				cond_resched();
-				this_cpu_inc(*ps.ppd->dd->send_schedule);
+				if (!irqs_disabled()) {
+					cond_resched();
+					this_cpu_inc(
+					   *ps.ppd->dd->send_schedule);
+				}
 				timeout = jiffies + (timeout_int) / 8;
 			}
 			spin_lock_irqsave(&qp->s_lock, flags);