btrfs: make btrfs_destroy_pinned_extent() return void

Currently btrfs_destroy_pinned_extent() is always returning 0 no matter
what and its caller ignores its return value (as well everything up in
the call chain). This is because this is called in the transaction abort
path, where we can't even deal with any errors since we are in a critical
situation already and cleanup of resources is done in a best effort
fashion.

So make btrfs_destroy_pinned_extent() return void.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -4743,12 +4743,11 @@ static void btrfs_destroy_marked_extents(struct btrfs_fs_info *fs_info,
 	}
 }
 
-static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
-				       struct extent_io_tree *unpin)
+static void btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
+					struct extent_io_tree *unpin)
 {
 	u64 start;
 	u64 end;
-	int ret;
 
 	while (1) {
 		struct extent_state *cached_state = NULL;
@@ -4760,9 +4759,8 @@ static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
 		 * the same extent range.
 		 */
 		mutex_lock(&fs_info->unused_bg_unpin_mutex);
-		ret = find_first_extent_bit(unpin, 0, &start, &end,
-					    EXTENT_DIRTY, &cached_state);
-		if (ret) {
+		if (find_first_extent_bit(unpin, 0, &start, &end,
+					  EXTENT_DIRTY, &cached_state)) {
 			mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 			break;
 		}
@@ -4773,8 +4771,6 @@ static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info,
 		mutex_unlock(&fs_info->unused_bg_unpin_mutex);
 		cond_resched();
 	}
-
-	return 0;
 }
 
 static void btrfs_cleanup_bg_io(struct btrfs_block_group *cache)