[util/hb-shape/hb-subset] Don't terminate on first error in batch mode

There's no reason to quit processing.  The failure is already
communicated via stdout in both cases.

util/hb-shape.cc

@@ -186,11 +186,7 @@ main (int argc, char **argv)
 
       driver_t<EOF> driver;
       ret |= driver.main (argc, args);
-
       fflush (stdout);
-
-      if (ret)
-	break;
     }
     return ret;
   }

util/hb-subset.cc

@@ -160,9 +160,6 @@ main (int argc, char **argv)
       fprintf (stdout, result == 0 ? "success\n" : "failure\n");
       fflush (stdout);
       ret |= result;
-
-      if (ret)
-	break;
     }
     return ret;
   }