oledlg: Only send the end dialog msg if the button is actually clicked.

dlls/oledlg/pastespl.c

@@ -605,8 +605,14 @@ static INT_PTR CALLBACK ps_dlg_proc(HWND hdlg, UINT msg, WPARAM wp, LPARAM lp)
             }
         case IDOK:
         case IDCANCEL:
+            switch(HIWORD(wp))
+            {
+            case BN_CLICKED:
                 send_end_dialog_msg(hdlg, ps_struct, LOWORD(wp));
                 return FALSE;
+            default:
+                return FALSE;
+            }
         }
         return FALSE;
     default: