lib/iommu-common.c: do not use 0xffffffffffffffffl for computing align_mask

Using a 64 bit constant generates "warning: integer constant is too
large for 'long' type" on 32 bit platforms.  Instead use ~0ul and
BITS_PER_LONG.

Detected by Andrew Morton on ARMD.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/iommu-common.c b/lib/iommu-common.c
index df30632..ff19f66 100644
--- a/lib/iommu-common.c
+++ b/lib/iommu-common.c
@@ -119,7 +119,7 @@
 	unsigned long align_mask = 0;
 
 	if (align_order > 0)
-		align_mask = 0xffffffffffffffffl >> (64 - align_order);
+		align_mask = ~0ul >> (BITS_PER_LONG - align_order);
 
 	/* Sanity check */
 	if (unlikely(npages == 0)) {