ceph: fix "ceph.dir.rctime" vxattr value

The vxattr value incorrectly places a "09" prefix to the nanoseconds
field, instead of providing it as a zero-pad width specifier after '%'.

Fixes: 3489b42 ("ceph: fix three bugs, two in ceph_vxattrcb_file_layout()")
Link: https://tracker.ceph.com/issues/39943
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/xattr.c

@@ -224,7 +224,7 @@ static size_t ceph_vxattrcb_dir_rbytes(struct ceph_inode_info *ci, char *val,
 static size_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
 				       size_t size)
 {
-	return snprintf(val, size, "%lld.09%ld", ci->i_rctime.tv_sec,
+	return snprintf(val, size, "%lld.%09ld", ci->i_rctime.tv_sec,
 			ci->i_rctime.tv_nsec);
 }