lj_bcread.c: Remove suspicious loop

Remove a loop in bcread_varinfo() that looks strange.

What is this loop supposed to do? The code doesn't make sense to me,
and this change is resolving a segfault problem.

src/lj_bcread.c

@@ -164,9 +164,7 @@ static void bcread_dbg(LexState *ls, GCproto *pt, MSize sizedbg)
 static const void *bcread_varinfo(GCproto *pt)
 {
   const uint8_t *p = proto_uvinfo(pt);
-  MSize n = pt->sizeuv;
-  if (n) while (*p++ || --n) ;
-  return p;
+  return p + pt->sizeuv;
 }
 
 /* Read a single constant key/value of a template table. */