orangefs: add splice file operations

Fix some xfstests regressions that started after 36e2c742,
"don't allow splice read/write without explicit ops". Thanks for
help from Dave Chinner and Matthew Wilcox.
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

fs/orangefs/file.c

@@ -663,6 +663,8 @@ const struct file_operations orangefs_file_operations = {
 	.unlocked_ioctl	= orangefs_ioctl,
 	.mmap		= orangefs_file_mmap,
 	.open		= generic_file_open,
+	.splice_read    = generic_file_splice_read,
+	.splice_write   = iter_file_splice_write,
 	.flush		= orangefs_flush,
 	.release	= orangefs_file_release,
 	.fsync		= orangefs_fsync,