Really force 1 entry per line with -1 in ls(1)

if a filename contains a \n, it would not be limited to one line.
We use the qflag to replace the control characters with '?'s.

ls.c

@@ -369,7 +369,8 @@ main(int argc, char *argv[])
 
 	ARGBEGIN {
 	case '1':
-		/* ignore */
+		/* force output to 1 entry per line */
+		qflag = 1;
 		break;
 	case 'A':
 		Aflag = 1;