fix ptty test program. don't quit after pos request

ptty.c

@@ -131,7 +131,7 @@ main(int argc, char *argv[])
 			/* handle cursor position request */
 			if (strcmp("\033[6n", buf) == 0) {
 				dprintf(mfd, "\033[1;25R", 1, 1);
-				break;
+				continue;
 			}
 
 			if (write(STDOUT_FILENO, buf, n) == -1)