Get rid of most instance of 'foo == NULL'

core/src/fxge/ge/fx_ge.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/include/fxge/fx_ge.h"
 
 #include "text_int.h"
 
@@ skipping 23 matching lines @@
   g_pGEModule->SetTextGamma(2.2f);
 }
 void CFX_GEModule::Use(CFX_GEModule* pModule) {
   g_pGEModule = pModule;
 }
 void CFX_GEModule::Destroy() {
   delete g_pGEModule;
   g_pGEModule = NULL;
 }
 CFX_FontCache* CFX_GEModule::GetFontCache() {
-  if (m_pFontCache == NULL) {
+  if (!m_pFontCache) {
     m_pFontCache = new CFX_FontCache();
   }
   return m_pFontCache;
 }
 void CFX_GEModule::SetTextGamma(FX_FLOAT gammaValue) {
   gammaValue /= 2.2f;
   int i = 0;
   while (i < 256) {
     m_GammaValue[i] =
         (uint8_t)(FXSYS_pow((FX_FLOAT)i / 255, gammaValue) * 255.0f + 0.5f);
     i++;
   }
 }
 const uint8_t* CFX_GEModule::GetTextGammaTable() {
   return m_GammaValue;
 }