[binder] Modernize codebase by replacing NULL with nullptr

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

Test: m
Bug: 68236239
Change-Id: Ibecc3b84c4e8c42cf65a0480ceb7c7bf1077866c
diff --git a/libs/binder/Value.cpp b/libs/binder/Value.cpp
index 2b263ed..a28a618 100644
--- a/libs/binder/Value.cpp
+++ b/libs/binder/Value.cpp
@@ -229,7 +229,7 @@
 #ifdef LIBBINDER_VALUE_SUPPORTS_TYPE_INFO
 const std::type_info& Value::type() const
 {
-    return mContent != NULL
+    return mContent != nullptr
         ? mContent->type()
         : typeid(void);
 }
@@ -306,7 +306,7 @@
 
 #define BEGIN_HANDLE_WRITE()                                                                      \
     do {                                                                                          \
-        const void* t_info(mContent?mContent->type_ptr():NULL);                                   \
+        const void* t_info(mContent?mContent->type_ptr():nullptr);                                \
         if (false) { }
 #define HANDLE_WRITE_TYPE(T, TYPEVAL, TYPEMETHOD)                                                 \
     else if (t_info == internal_type_ptr<T>()) {                                                  \