ceph: switch to iter_file_splice_write()

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

fs/ceph/file.c

@@ -1244,7 +1244,7 @@ const struct file_operations ceph_file_fops = {
 	.lock = ceph_lock,
 	.flock = ceph_flock,
 	.splice_read = generic_file_splice_read,
-	.splice_write = generic_file_splice_write,
+	.splice_write = iter_file_splice_write,
 	.unlocked_ioctl = ceph_ioctl,
 	.compat_ioctl	= ceph_ioctl,
 	.fallocate	= ceph_fallocate,