Add missing t_str() call to fix wxUSE_STL build after r73792.

Don't rely on implicit conversion from wxString to wxChar* which is not
available in all builds.

Closes #15145.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73808 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/msw/dlmsw.cpp

@@ -377,7 +377,7 @@ WXHMODULE wxDynamicLibrary::MSWGetModuleHandle(const wxString& name, void *addr)
             return hmod;
     }
 
-    return ::GetModuleHandle(name);
+    return ::GetModuleHandle(name.t_str());
 }
 
 #endif // wxUSE_DYNLIB_CLASS