Remove NULL in xfa/

xfa/fwl/basewidget/fwl_monthcalendarimp.cpp

Index: xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
diff --git a/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp b/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
index 209a857dade2fd1700f940638e71899eb99817c5..ca141a2d7ad7b751726e3bd0cf878ce7f520132f 100644
--- a/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
+++ b/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
@@ -235,7 +235,7 @@ FWL_Error CFWL_MonthCalendarImp::DrawWidget(CFX_Graphics* pGraphics,
                                             const CFX_Matrix* pMatrix) {
   if (!pGraphics)
     return FWL_Error::Indefinite;
-  if (m_pProperties->m_pThemeProvider == NULL) {
+  if (!m_pProperties->m_pThemeProvider) {
     m_pProperties->m_pThemeProvider = GetAvailableTheme();
   }
   IFWL_ThemeProvider* pTheme = m_pProperties->m_pThemeProvider;