ntfs: remove ntfs_file_write

do_sync_write() does the right thing for turning the aio_writev method
into a normal non-vectored synchronous write, no need to duplicate it in
ntfs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>