btrfs: make clear_extent_buffer_uptodate return void

Does not return any errors, nor anything from the callgraph.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/extent_io.c

@@ -5227,7 +5227,7 @@ int set_extent_buffer_dirty(struct extent_buffer *eb)
 	return was_dirty;
 }
 
-int clear_extent_buffer_uptodate(struct extent_buffer *eb)
+void clear_extent_buffer_uptodate(struct extent_buffer *eb)
 {
 	unsigned long i;
 	struct page *page;
@@ -5240,7 +5240,6 @@ int clear_extent_buffer_uptodate(struct extent_buffer *eb)
 		if (page)
 			ClearPageUptodate(page);
 	}
-	return 0;
 }
 
 void set_extent_buffer_uptodate(struct extent_buffer *eb)

fs/btrfs/extent_io.h

@@ -331,7 +331,7 @@ void memset_extent_buffer(struct extent_buffer *eb, char c,
 void clear_extent_buffer_dirty(struct extent_buffer *eb);
 int set_extent_buffer_dirty(struct extent_buffer *eb);
 void set_extent_buffer_uptodate(struct extent_buffer *eb);
-int clear_extent_buffer_uptodate(struct extent_buffer *eb);
+void clear_extent_buffer_uptodate(struct extent_buffer *eb);
 int extent_buffer_uptodate(struct extent_buffer *eb);
 int extent_buffer_under_io(struct extent_buffer *eb);
 int map_private_extent_buffer(struct extent_buffer *eb, unsigned long offset,