8199156: Better route routing

Reviewed-by: igerasim, mschoene, michaelm, rhalade

src/java.base/unix/native/libnet/net_util_md.c

@@ -584,6 +584,8 @@ static void initLoopbackRoutes() {
 
                 if (loRoutesTemp == 0) {
                     free(loRoutes);
+                    loRoutes = NULL;
+                    nRoutes = 0;
                     fclose (f);
                     return;
                 }