ntfs: use is_power_of_2() function for clarity.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ntfs/logfile.c b/fs/ntfs/logfile.c
index d7932e9..89b0298 100644
--- a/fs/ntfs/logfile.c
+++ b/fs/ntfs/logfile.c
@@ -26,6 +26,7 @@
 #include <linux/highmem.h>
 #include <linux/buffer_head.h>
 #include <linux/bitops.h>
+#include <linux/log2.h>
 
 #include "attrib.h"
 #include "aops.h"
@@ -65,7 +66,7 @@
 			logfile_log_page_size < NTFS_BLOCK_SIZE ||
 			logfile_system_page_size &
 			(logfile_system_page_size - 1) ||
-			logfile_log_page_size & (logfile_log_page_size - 1)) {
+			!is_power_of_2(logfile_log_page_size)) {
 		ntfs_error(vi->i_sb, "$LogFile uses unsupported page size.");
 		return false;
 	}