There is only one kind of write_begin/write_end aops, so we don't need
to look up which aop it is, just make hfs_write_begin() available to
this file and call it directly.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>