block: remove per-queue plugging

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

fs/jfs/jfs_metapage.c

@@ -583,7 +583,6 @@ static void metapage_invalidatepage(struct page *page, unsigned long offset)
 const struct address_space_operations jfs_metapage_aops = {
 	.readpage	= metapage_readpage,
 	.writepage	= metapage_writepage,
-	.sync_page	= block_sync_page,
 	.releasepage	= metapage_releasepage,
 	.invalidatepage	= metapage_invalidatepage,
 	.set_page_dirty	= __set_page_dirty_nobuffers,