IB/qib: Modify software pma counters to use percpu variables

The counters, unicast_xmit, unicast_rcv, multicast_xmit, multicast_rcv
are now maintained as percpu variables.

The mad code is modified to add a z_ latch so that the percpu counters
monotonically increase with appropriate adjustments in the reset,
read logic to maintain the z_ latch.

This patch also corrects the fact the unitcast_xmit wasn't handled
at all for UC and RC QPs.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/qib/qib_iba7220.c b/drivers/infiniband/hw/qib/qib_iba7220.c
index 28063d4..7dec89f 100644
--- a/drivers/infiniband/hw/qib/qib_iba7220.c
+++ b/drivers/infiniband/hw/qib/qib_iba7220.c
@@ -4059,7 +4059,9 @@
 	init_waitqueue_head(&cpspec->autoneg_wait);
 	INIT_DELAYED_WORK(&cpspec->autoneg_work, autoneg_7220_work);
 
-	qib_init_pportdata(ppd, dd, 0, 1);
+	ret = qib_init_pportdata(ppd, dd, 0, 1);
+	if (ret)
+		goto bail;
 	ppd->link_width_supported = IB_WIDTH_1X | IB_WIDTH_4X;
 	ppd->link_speed_supported = QIB_IB_SDR | QIB_IB_DDR;