Print name(of thread) also in mtr_report, testserver does not set name

so it will still look the same, but makes debugging much easier

mysql-test/lib/mtr_report.pm

@@ -434,7 +434,7 @@ sub _timestamp {
 sub mtr_report (@) {
   if (defined $verbose)
   {
-    print join(" ", @_), "\n";
+    print $name, join(" ", @_), "\n";
   }
 }