vm.c: unnecessary condition

* vm.c (vm_stat): remove unnecessary condition, when argc != 1 arg
  is always Qnil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56039 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm.c

@@ -396,7 +396,7 @@ vm_stat(int argc, VALUE *argv, VALUE self)
 	else
 	    rb_raise(rb_eTypeError, "non-hash or symbol given");
     }
-    else if (NIL_P(arg)) {
+    else {
 	hash = rb_hash_new();
     }