Check old tmpfiles.d when removing package

When removing package, will also remove the generated tmpfile
config under the rpm-ostree tmpfiles.d directory. Since coreos#4697,
we use the new directory like `usr/lib/rpm-ostree/tmpfiles.d`, but
for old `usr/lib/tmpfiles.d`, failed with `error: opendir(usr/lib/
rpm-ostree/tmpfiles.d): No such file or directory`.

With this patch, check if `usr/lib/rpm-ostree/tmpfiles.d` does not
exist, will use old `usr/lib/tmpfiles.d` instead.
Also needs coreos#4727.
Fixes: fedora-silverblue/issue-tracker#523

src/libpriv/rpmostree-core.cxx

@@ -3086,10 +3086,25 @@ delete_package_from_root (RpmOstreeContext *self, rpmte pkg, int rootfs_dfd, GHa
     }
 
   /* And finally, delete any automatically generated tmpfiles.d dropin. */
+  const char *tmpfiles_path = "usr/lib/rpm-ostree/tmpfiles.d";
+  /* Check if the new rpm-ostree tmpfiles.d directory exists;
+   * if not, switch to old tmpfiles.d directory.
+   */
+  if (!glnx_fstatat_allow_noent (rootfs_dfd, tmpfiles_path, NULL, AT_SYMLINK_NOFOLLOW, error))
+    return FALSE;
   glnx_autofd int tmpfiles_dfd = -1;
-  if (!glnx_opendirat (rootfs_dfd, "usr/lib/rpm-ostree/tmpfiles.d", TRUE, &tmpfiles_dfd, error))
+  g_autofree char *dropin = NULL;
+  if (errno == 0)
+    {
+      dropin = g_strdup_printf ("%s.conf", rpmteN (pkg));
+    }
+  else if (errno == ENOENT)
+    {
+      tmpfiles_path = "usr/lib/tmpfiles.d";
+      dropin = g_strdup_printf ("pkg-%s.conf", rpmteN (pkg));
+    }
+  if (!glnx_opendirat (rootfs_dfd, tmpfiles_path, TRUE, &tmpfiles_dfd, error))
     return FALSE;
-  g_autofree char *dropin = g_strdup_printf ("%s.conf", rpmteN (pkg));
   if (!glnx_shutil_rm_rf_at (tmpfiles_dfd, dropin, cancellable, error))
     return FALSE;