hpfs: add fstrim support

This patch adds support for fstrim to the HPFS filesystem.

Signed-off-by: Mikulas Patocka <mikulas@twibright.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/hpfs/dir.c b/fs/hpfs/dir.c
index 2a8e074..dc540bf 100644
--- a/fs/hpfs/dir.c
+++ b/fs/hpfs/dir.c
@@ -327,4 +327,5 @@
 	.iterate	= hpfs_readdir,
 	.release	= hpfs_dir_release,
 	.fsync		= hpfs_file_fsync,
+	.unlocked_ioctl	= hpfs_ioctl,
 };