[ruby/win32ole] Fix typos [ci skip]

https://github.com/ruby/win32ole/commit/8d46bd0c93

ext/win32ole/win32ole_method.c

@@ -437,7 +437,7 @@ ole_method_invoke_kind(ITypeInfo *pTypeInfo, UINT method_index)
 
 /*
  *   call-seq:
- *      WIN32OLE_MTHOD#invkind
+ *      WIN32OLE_METHOD#invkind
  *
  *   Returns the method invoke kind.
  *     tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbooks')

test/win32ole/test_win32ole.rb

@@ -101,7 +101,7 @@ if defined?(WIN32OLE)
       assert_include(mnames, 'Count')
     end
 
-    def test_ole_mehtod_help
+    def test_ole_method_help
       minfo = @dict1.ole_method_help("Add")
       assert_equal(2, minfo.size_params)
     end