[GFS2] Add sync_page to metadata address space operations

This set of address space operations was missing a sync_page
operation.
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/gfs2/meta_io.c

@@ -50,6 +50,7 @@ static int gfs2_aspace_writepage(struct page *page,
 static const struct address_space_operations aspace_aops = {
 	.writepage = gfs2_aspace_writepage,
 	.releasepage = gfs2_releasepage,
+	.sync_page = block_sync_page,
 };
 
 /**