remove the code to silence lint

Warning facilities on recent compilers are incredibly improved,
so the code to silence "good-old" lint is much less sense.

src/hack.c

@@ -414,13 +414,8 @@ moverock(void)
             }
 
             {
-#ifdef LINT /* static long lastmovetime; */
-                long lastmovetime;
-                lastmovetime = 0;
-#else
                 /* note: reset to zero after save/restore cycle */
                 static NEARDATA long lastmovetime;
-#endif
  dopush:
                 what = the(xname(otmp));
                 if (!u.usteed) {