tmpfiles: Consider ENOPKG as information not available

We already handle the case where /etc/machine-id is empty. Let's make
sure we also handle the case where /etc/machine-id is "uninitialized".

(cherry picked from commit 5dd814d)
(cherry picked from commit faaa0ee)

Author: DaanDeMeyer

src/tmpfiles/tmpfiles.c

@@ -233,6 +233,7 @@ static inline bool ERRNO_IS_NOINFO(int r) {
         return IN_SET(abs(r),
                       EUNATCH,    /* os-release or machine-id missing */
                       ENOMEDIUM,  /* machine-id or another file empty */
+                      ENOPKG,     /* machine-id is uninitialized */
                       ENXIO);     /* env var is unset */
 }