UBI: avoid unnecessary division operations

UBI already checks that @min io size is the power of 2 at io_init.
It is save to use bit operations then.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/drivers/mtd/ubi/kapi.c b/drivers/mtd/ubi/kapi.c
index a70d588..5150883 100644
--- a/drivers/mtd/ubi/kapi.c
+++ b/drivers/mtd/ubi/kapi.c
@@ -397,8 +397,8 @@
 		return -EROFS;
 
 	if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
-	    offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
-	    len % ubi->min_io_size)
+	    offset + len > vol->usable_leb_size ||
+	    offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
 		return -EINVAL;
 
 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
@@ -447,7 +447,7 @@
 		return -EROFS;
 
 	if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
-	    len > vol->usable_leb_size || len % ubi->min_io_size)
+	    len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
 		return -EINVAL;
 
 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&