mmcli,ussd: don't rely on lock status to allow actions

Commit 001f35234e fixed this very same thing in
all the other interface actions, but 3GPP USSD actions were not fixed.

https://bugs.freedesktop.org/show_bug.cgi?id=97954

cli/mmcli-modem-3gpp.c

@@ -178,8 +178,8 @@ ensure_modem_3gpp (void)
 static void
 ensure_modem_3gpp_ussd (void)
 {
-    if (mm_modem_get_unlock_required (mm_object_peek_modem (ctx->object)) != MM_MODEM_LOCK_NONE) {
-        g_printerr ("error: modem not unlocked yet\n");
+    if (mm_modem_get_state (mm_object_peek_modem (ctx->object)) < MM_MODEM_STATE_ENABLED) {
+        g_printerr ("error: modem not enabled yet\n");
         exit (EXIT_FAILURE);
     }