btrfs: use IS_ALIGNED() for assertion in btrfs_lookup_csums_range() for simplicity

btrfs_lookup_csums_range() uses ALIGN() to check if "start"
and "end + 1" are aligned to "root->sectorsize". It's better to
replace these with IS_ALIGNED() for simplicity.
Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/file-item.c

@@ -329,8 +329,8 @@ int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
 	u64 csum_end;
 	u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
 
-	ASSERT(start == ALIGN(start, root->sectorsize) &&
-	       (end + 1) == ALIGN(end + 1, root->sectorsize));
+	ASSERT(IS_ALIGNED(start, root->sectorsize) &&
+	       IS_ALIGNED(end + 1, root->sectorsize));
 
 	path = btrfs_alloc_path();
 	if (!path)