journalctl: add a missing 'break'

There is a 'break' missing in the -q handling
so, for example, 'systemd-journalctl --new-id128 -q'
does nothing.

This patch fixes the problem.

src/journal/journalctl.c

@@ -148,6 +148,7 @@ static int parse_argv(int argc, char *argv[]) {
 
                 case 'q':
                         arg_quiet = true;
+                        break;
 
                 case '?':
                         return -EINVAL;