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

fpdfsdk/src/fpdf_sysfontinfo.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 "public/fpdf_sysfontinfo.h"
 
 #include "fpdfsdk/include/fsdk_define.h"
 #include "fpdfsdk/include/pdfwindow/PWL_FontMap.h"
@@ skipping 37 matching lines @@
   FX_DWORD GetFontData(void* hFont,
                        FX_DWORD table,
                        uint8_t* buffer,
                        FX_DWORD size) override {
     if (m_pInfo->GetFontData)
       return m_pInfo->GetFontData(m_pInfo, hFont, table, buffer, size);
     return 0;
   }
 
   FX_BOOL GetFaceName(void* hFont, CFX_ByteString& name) override {
-    if (m_pInfo->GetFaceName == NULL)
+    if (!m_pInfo->GetFaceName)
       return FALSE;
     FX_DWORD size = m_pInfo->GetFaceName(m_pInfo, hFont, NULL, 0);
     if (size == 0)
       return FALSE;
     char* buffer = FX_Alloc(char, size);
     size = m_pInfo->GetFaceName(m_pInfo, hFont, buffer, size);
     name = CFX_ByteString(buffer, size);
     FX_Free(buffer);
     return TRUE;
   }
@@ skipping 94 matching lines @@
     return 0;
   return charset;
 }
 
 static void DefaultDeleteFont(struct _FPDF_SYSFONTINFO* pThis, void* hFont) {
   ((FPDF_SYSFONTINFO_DEFAULT*)pThis)->m_pFontInfo->DeleteFont(hFont);
 }
 
 DLLEXPORT FPDF_SYSFONTINFO* STDCALL FPDF_GetDefaultSystemFontInfo() {
   IFX_SystemFontInfo* pFontInfo = IFX_SystemFontInfo::CreateDefault(nullptr);
-  if (pFontInfo == NULL)
+  if (!pFontInfo)
     return NULL;
 
   FPDF_SYSFONTINFO_DEFAULT* pFontInfoExt =
       FX_Alloc(FPDF_SYSFONTINFO_DEFAULT, 1);
   pFontInfoExt->DeleteFont = DefaultDeleteFont;
   pFontInfoExt->EnumFonts = DefaultEnumFonts;
   pFontInfoExt->GetFaceName = DefaultGetFaceName;
   pFontInfoExt->GetFont = DefaultGetFont;
   pFontInfoExt->GetFontCharset = DefaultGetFontCharset;
   pFontInfoExt->GetFontData = DefaultGetFontData;
   pFontInfoExt->MapFont = DefaultMapFont;
   pFontInfoExt->Release = DefaultRelease;
   pFontInfoExt->version = 1;
   pFontInfoExt->m_pFontInfo = pFontInfo;
   return pFontInfoExt;
 }