Make SkTInternalLList::validate validate all nodes

include/core/SkTInternalLList.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTInternalLList_DEFINED
 #define SkTInternalLList_DEFINED
 
@@ skipping 209 matching lines @@
         }
 
     private:
         T* fCurr;
     };
 
 #ifdef SK_DEBUG
     void validate() const {
         SkASSERT(!fHead == !fTail);
         Iter iter;
-        for (T* item = iter.init(*this, Iter::kHead_IterStart); NULL != (item = iter.next()); ) {
+        for (T* item = iter.init(*this, Iter::kHead_IterStart); NULL != item; item = iter.next()) {
             SkASSERT(this->isInList(item));
             if (NULL == item->fPrev) {
                 SkASSERT(fHead == item);
             } else {
                 SkASSERT(item->fPrev->fNext == item);
             }
             if (NULL == item->fNext) {
                 SkASSERT(fTail == item);
             } else {
                 SkASSERT(item->fNext->fPrev == item);
@@ skipping 22 matching lines @@
 #endif // SK_DEBUG
 
 private:
     T* fHead;
     T* fTail;
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif