IB/qib: Avoid variable-length array

Rather than use a variable size array allocation on the stack,
define a constant for the maximum array size possible.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/qib/qib_tx.c b/drivers/infiniband/hw/qib/qib_tx.c
index af30232..7f36454 100644
--- a/drivers/infiniband/hw/qib/qib_tx.c
+++ b/drivers/infiniband/hw/qib/qib_tx.c
@@ -170,7 +170,7 @@
 void qib_disarm_piobufs_set(struct qib_devdata *dd, unsigned long *mask,
 			    unsigned cnt)
 {
-	struct qib_pportdata *ppd, *pppd[dd->num_pports];
+	struct qib_pportdata *ppd, *pppd[QIB_MAX_IB_PORTS];
 	unsigned i;
 	unsigned long flags;