reuse Clear() instead of duplicating its code in Close()

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38396 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/textbuf.cpp

@@ -268,9 +268,7 @@ wxTextFileType wxTextBuffer::GuessType() const
 
 bool wxTextBuffer::Close()
 {
-    m_aTypes.Clear();
-    m_aLines.Clear();
-    m_nCurLine = 0;
+    Clear();
     m_isOpened = false;
 
     return true;