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/efs/inode.c

@@ -23,7 +23,6 @@ static sector_t _efs_bmap(struct address_space *mapping, sector_t block)
 }
 static const struct address_space_operations efs_aops = {
 	.readpage = efs_readpage,
-	.sync_page = block_sync_page,
 	.bmap = _efs_bmap
 };