btrfs: remove total_data_size variable in btrfs_batch_insert_items()

clang warns:

  fs/btrfs/delayed-inode.c:684:6: warning: variable 'total_data_size' set
  but not used [-Wunused-but-set-variable]
	  int total_data_size = 0, total_size = 0;
	      ^
  1 warning generated.

This variable's value has been unused since commit fc0d82e ("btrfs:
sink total_data parameter in setup_items_for_insert"). Eliminate it.

Link: ClangBuiltLinux#1391
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/delayed-inode.c

@@ -681,7 +681,7 @@ static int btrfs_batch_insert_items(struct btrfs_root *root,
 {
 	struct btrfs_delayed_item *curr, *next;
 	int free_space;
-	int total_data_size = 0, total_size = 0;
+	int total_size = 0;
 	struct extent_buffer *leaf;
 	char *data_ptr;
 	struct btrfs_key *keys;
@@ -706,7 +706,6 @@ static int btrfs_batch_insert_items(struct btrfs_root *root,
 	 */
 	while (total_size + next->data_len + sizeof(struct btrfs_item) <=
 	       free_space) {
-		total_data_size += next->data_len;
 		total_size += next->data_len + sizeof(struct btrfs_item);
 		list_add_tail(&next->tree_list, &head);
 		nitems++;