cut: Fix out of boundary write on illegal list argument

It is possible to trigger an out of boundary write in cut if an invalid
range with autostart has been supplied.

PR:		227330
Submitted by:	tobias@stoeckmann.org

usr.bin/cut/cut.c

@@ -210,6 +210,12 @@ get_list(char *list)
 		needpos(maxval + 1);
 	}
 
+	/* reversed range with autostart */
+	if (maxval < autostart) {
+		maxval = autostart;
+		needpos(maxval + 1);
+	}
+
 	/* set autostart */
 	if (autostart)
 		memset(positions + 1, '1', autostart);