Fix harmless g++ warning about using NULL for non-pointer.

PostQueuedCompletionStatus() may be either an int or a pointer, pass 0 instead
of NULL when we don't care about its value anyhow.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62678 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/private/fswatcher.h

@@ -161,7 +161,7 @@ public:
     {
         wxCHECK_MSG( m_iocp != INVALID_HANDLE_VALUE, false, "IOCP not init" );
 
-        int ret = PostQueuedCompletionStatus(m_iocp, 0, NULL, NULL);
+        int ret = PostQueuedCompletionStatus(m_iocp, 0, 0, NULL);
         if (!ret)
         {
             wxLogSysError(_("Unable to post completion status"));