xbps_get_pkg_plist_from_binpkg: fix a double free, found by Gottox.

xbps-query -Rf foo without network was enough to trigger it.

NEWS

@@ -1,5 +1,8 @@
 xbps-0.38 (???):
 
+ * xbps-query(8): fix a segfault with -Rf when there's no network connectivity.
+   Reported by Gottox.
+
  * xbps-uchroot(8): do not remount / unnecessarily; just mount it as private
    and nosuid once; this is enough for our use cases.
 

lib/plist_fetch.c

@@ -101,7 +101,6 @@ open_archive_by_url(struct url *url)
 
 	if (archive_read_open(a, f, fetch_archive_open, fetch_archive_read,
 	    fetch_archive_close)) {
-		free(f);
 		archive_read_finish(a);
 		return NULL;
 	}