Btrfs: make inode.c:submit_compressed_extents() return void

Its return value is completely ignored by its single caller and it's
useless anyway, since errors are indicated through SetPageError and
the bit AS_EIO set in the flags of the inode's mapping. The caller
can't do anything with the value, as it's invoked from a workqueue
task and not by the task calling filemap_fdatawrite_range (which calls
the writepages address space callback, which in turn calls the inode's
fill_delalloc callback).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/inode.c

@@ -655,7 +655,7 @@ static void free_async_extent_pages(struct async_extent *async_extent)
  * queued.  We walk all the async extents created by compress_file_range
  * and send them down to the disk.
  */
-static noinline int submit_compressed_extents(struct inode *inode,
+static noinline void submit_compressed_extents(struct inode *inode,
 					      struct async_cow *async_cow)
 {
 	struct async_extent *async_extent;
@@ -667,9 +667,6 @@ static noinline int submit_compressed_extents(struct inode *inode,
 	struct extent_io_tree *io_tree;
 	int ret = 0;
 
-	if (list_empty(&async_cow->extents))
-		return 0;
-
 again:
 	while (!list_empty(&async_cow->extents)) {
 		async_extent = list_entry(async_cow->extents.next,
@@ -841,7 +838,7 @@ retry:
 		kfree(async_extent);
 		cond_resched();
 	}
-	return 0;
+	return;
 out_free_reserve:
 	btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
 out_free: