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

core/src/fdrm/crypto/fx_crypt_sha.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/fdrm/fx_crypt.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ skipping 351 matching lines @@
   CRYPT_SHA256Start(&ctx);
   CRYPT_SHA256Update(&ctx, data, size);
   CRYPT_SHA256Finish(&ctx, digest);
 }
 typedef struct {
   uint64_t total[2];
   uint64_t state[8];
   uint8_t buffer[128];
 } sha384_context;
 uint64_t FX_ato64i(const FX_CHAR* str) {
-  FXSYS_assert(str != NULL);
+  FXSYS_assert(str);
   uint64_t ret = 0;
   int len = (int)FXSYS_strlen(str);
   len = len > 16 ? 16 : len;
   for (int i = 0; i < len; ++i) {
     if (i) {
       ret <<= 4;
     }
     if (str[i] >= '0' && str[i] <= '9') {
       ret |= (str[i] - '0') & 0xFF;
     } else if (str[i] >= 'a' && str[i] <= 'f') {
@@ skipping 265 matching lines @@
                           FX_DWORD size,
                           uint8_t digest[64]) {
   sha384_context context;
   CRYPT_SHA512Start(&context);
   CRYPT_SHA512Update(&context, data, size);
   CRYPT_SHA512Finish(&context, digest);
 }
 #ifdef __cplusplus
 };
 #endif