adding wxFALLTHROUGH where until now we had comments, allows for code-analysis support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76399 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/string.cpp

@@ -2201,7 +2201,7 @@ bool wxString::Matches(const wxString& mask) const
                 // (however note that we don't quote '[' and ']' to allow
                 // using them for Unix shell like matching)
                 pattern += wxT('\\');
-                // fall through
+                wxFALLTHROUGH;
 
             default:
                 pattern += *pszMask;