Put the printf of failed ratio on itäs only line, printf was tricked

into thinking the escaped % + w was a format specifier

mysql-test/lib/mtr_report.pl

@@ -203,8 +203,9 @@ sub mtr_report_stats ($) {
   else
   {
     my $ratio=  $tot_passed * 100 / $tot_tests;
-    printf "Failed $tot_failed/$tot_tests tests, " .
-      "%.2f\% were successful.\n\n", $ratio;
+    print "Failed $tot_failed/$tot_tests tests, ";
+    printf("%.2f", $ratio);
+    print "\% were successful.\n\n";
     print
       "The log files in var/log may give you some hint\n",
       "of what went wrong.\n",