is_power_of_2 in fat

Replacing (n & (n-1)) in the context of power of 2 checks with
is_power_of_2

Signed-off-by: vignesh babu <vignesh.babu@wipro.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fat/inode.c

@@ -25,6 +25,7 @@
 #include <linux/parser.h>
 #include <linux/uio.h>
 #include <linux/writeback.h>
+#include <linux/log2.h>
 #include <asm/unaligned.h>
 
 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
@@ -1217,8 +1218,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 	}
 	logical_sector_size =
 		le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
-	if (!logical_sector_size
-	    || (logical_sector_size & (logical_sector_size - 1))
+	if (!is_power_of_2(logical_sector_size)
 	    || (logical_sector_size < 512)
 	    || (PAGE_CACHE_SIZE < logical_sector_size)) {
 		if (!silent)
@@ -1228,8 +1228,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent,
 		goto out_invalid;
 	}
 	sbi->sec_per_clus = b->sec_per_clus;
-	if (!sbi->sec_per_clus
-	    || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
+	if (!is_power_of_2(sbi->sec_per_clus)) {
 		if (!silent)
 			printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
 			       sbi->sec_per_clus);