dm: use is_power_of_2

Replacing n & (n - 1) for power of 2 check by is_power_of_2(n)

Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 6f60f30..2b2ca37 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -19,6 +19,7 @@
 #include <linux/time.h>
 #include <linux/vmalloc.h>
 #include <linux/workqueue.h>
+#include <linux/log2.h>
 
 #define DM_MSG_PREFIX "raid1"
 #define DM_IO_PAGES 64
@@ -995,7 +996,7 @@
 
 static inline int _check_region_size(struct dm_target *ti, uint32_t size)
 {
-	return !(size % (PAGE_SIZE >> 9) || (size & (size - 1)) ||
+	return !(size % (PAGE_SIZE >> 9) || !is_power_of_2(size) ||
 		 size > ti->len);
 }