[binder] Replace NULL/0 with nullptr

Fixes -Wzero-as-null-pointer-constant warning.

clang-tidy -checks=modernize-use-nullptr -p compile_commands.json -fix
...

Test: m
Bug: 68236239
Change-Id: I3181bc5683796423a98b0f9b94daf30880c07bdc
Merged-In: I3181bc5683796423a98b0f9b94daf30880c07bdc
(cherry picked from commit 91635563b8a1bf7a31e4ceb439728dacb79abd76)
diff --git a/libs/binder/MemoryDealer.cpp b/libs/binder/MemoryDealer.cpp
index 1cfe02a..eacad3b 100644
--- a/libs/binder/MemoryDealer.cpp
+++ b/libs/binder/MemoryDealer.cpp
@@ -52,8 +52,8 @@
     NODE*  mLast;
 
 public:
-                LinkedList() : mFirst(0), mLast(0) { }
-    bool        isEmpty() const { return mFirst == 0; }
+                LinkedList() : mFirst(nullptr), mLast(nullptr) { }
+    bool        isEmpty() const { return mFirst == nullptr; }
     NODE const* head() const { return mFirst; }
     NODE*       head() { return mFirst; }
     NODE const* tail() const { return mLast; }
@@ -62,7 +62,7 @@
     void insertAfter(NODE* node, NODE* newNode) {
         newNode->prev = node;
         newNode->next = node->next;
-        if (node->next == 0) mLast = newNode;
+        if (node->next == nullptr) mLast = newNode;
         else                 node->next->prev = newNode;
         node->next = newNode;
     }
@@ -70,17 +70,17 @@
     void insertBefore(NODE* node, NODE* newNode) {
          newNode->prev = node->prev;
          newNode->next = node;
-         if (node->prev == 0)   mFirst = newNode;
+         if (node->prev == nullptr)   mFirst = newNode;
          else                   node->prev->next = newNode;
          node->prev = newNode;
     }
 
     void insertHead(NODE* newNode) {
-        if (mFirst == 0) {
+        if (mFirst == nullptr) {
             mFirst = mLast = newNode;
-            newNode->prev = newNode->next = 0;
+            newNode->prev = newNode->next = nullptr;
         } else {
-            newNode->prev = 0;
+            newNode->prev = nullptr;
             newNode->next = mFirst;
             mFirst->prev = newNode;
             mFirst = newNode;
@@ -99,9 +99,9 @@
     }
 
     NODE* remove(NODE* node) {
-        if (node->prev == 0)    mFirst = node->next;
+        if (node->prev == nullptr)    mFirst = node->next;
         else                    node->prev->next = node->next;
-        if (node->next == 0)    mLast = node->prev;
+        if (node->next == nullptr)    mLast = node->prev;
         else                    node->next->prev = node->prev;
         return node;
     }
@@ -141,7 +141,7 @@
 
     struct chunk_t {
         chunk_t(size_t start, size_t size)
-        : start(start), size(size), free(1), prev(0), next(0) {
+        : start(start), size(size), free(1), prev(nullptr), next(nullptr) {
         }
         size_t              start;
         size_t              size : 28;
@@ -329,7 +329,7 @@
         return 0;
     }
     size = (size + kMemoryAlign-1) / kMemoryAlign;
-    chunk_t* free_chunk = 0;
+    chunk_t* free_chunk = nullptr;
     chunk_t* cur = mList.head();
 
     size_t pagesize = getpagesize();
@@ -418,7 +418,7 @@
         }
         cur = cur->next;
     }
-    return 0;
+    return nullptr;
 }
 
 void SimpleBestFitAllocator::dump(const char* what) const