pg_upgrade: Fix fatal error handling

Restore exiting when pg_log(PG_FATAL) is called directly instead of
calling pg_fatal().  Fault introduced in
264aa14a.

contrib/pg_upgrade/util.c

@@ -131,6 +131,8 @@ pg_log_v(eLogType type, const char *fmt, va_list ap)
 
 		case PG_FATAL:
 			printf("\n%s", _(message));
+			printf("Failure, exiting\n");
+			exit(1);
 			break;
 
 		default: