Bug #41649 sporadic pb failure: mtr stopped, message "TIMEOUT (1200 seconds), ABORTING."

Potentially infinite loop in check_expected_crash_and_restart 
Replace with finite loop and some additional logic

mysql-test/lib/My/SafeProcess.pm

@@ -537,6 +537,24 @@ sub wait_any {
 }
 
 #
+# Check if any process has exited, but don't wait.
+#
+# Returns a reference to the SafeProcess that
+# exited or undefined
+#
+sub check_any {
+  for my $proc (values %running){
+    if ( $proc->is_child($$) ) {
+      if (not $proc->wait_one(0)) {
+	_verbose ("Found exited $proc");
+	return $proc;
+      }
+    }
+  }
+  return undef;
+}
+
+
 # Overload string operator
 # and fallback to default functions if no
 # overloaded function is found