fs/hfsplus/wrapper.c: replace shift loop by ilog2

Replace while blocksize;shift by ilog2
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/hfsplus/wrapper.c

@@ -231,9 +231,7 @@ int hfsplus_read_wrapper(struct super_block *sb)
 	if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
 		goto out_free_backup_vhdr;
 	sbi->alloc_blksz = blocksize;
-	sbi->alloc_blksz_shift = 0;
-	while ((blocksize >>= 1) != 0)
-		sbi->alloc_blksz_shift++;
+	sbi->alloc_blksz_shift = ilog2(blocksize);
 	blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE);
 
 	/*