Fix passing wxCStrData to a vararg function.

This doesn't work with simple vararg functions and the real solution would be
to use WX_DEFINE_VARARG_FUNC for wxCrashReport::Output() but for now just add
a cast to make the code compile and work with minimal changes.

Closes #15598.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75060 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/crashrpt.cpp

@@ -226,7 +226,9 @@ bool wxCrashReportImpl::Generate(int flags, EXCEPTION_POINTERS *ep)
     }
     else // dbghelp.dll couldn't be loaded
     {
-        Output(wxT("%s"), wxDbgHelpDLL::GetErrorMessage().c_str());
+        Output(wxT("%s"), static_cast<const wxChar*>(
+                    wxDbgHelpDLL::GetErrorMessage().c_str()
+              ));
     }
 #else // !wxUSE_DBGHELP
     wxUnusedVar(flags);