win32ole.c: fix long conversion

* ext/win32ole/win32ole.c (ole_val2variant): reuse the converted
  result for V_I8.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55889 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ext/win32ole/win32ole.c

@@ -1275,7 +1275,7 @@ ole_val2variant(VALUE val, VARIANT *var)
             V_I4(var) = (LONG)v;
 #if SIZEOF_LONG > 4
             if (V_I4(var) != v) {
-                V_I8(var) = NUM2LONG(val);
+                V_I8(var) = v;
                 V_VT(var) = VT_I8;
             }
 #endif