Bugfix in handbrake process status code check

Inverted check on handbrake process return status caused rip to report
incorrect completion status

handbrake-cluster-worker.pl

@@ -131,7 +131,7 @@ sub do_rip {
     waitpid($child_pid, 0);
     my $child_exit_status = $? >> 8;
 
-    if (!$child_exit_status) {
+    if ($child_exit_status) {
         $log->warning("Ripping process returned error status: $child_exit_status");
         return undef;
     }