Get rid of NULLs 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 e8672e67dc0b68b3357bb6b3d7f2776a4a30bca7..112f396cf958c8102dd0ed3e3ceb138a191e6d78 100644
--- a/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
+++ b/xfa/fwl/basewidget/fwl_monthcalendarimp.cpp
@@ -235,9 +235,9 @@ 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;
   if (HasBorder()) {
     DrawBorder(pGraphics, CFWL_Part::Border, pTheme, pMatrix);