[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
diff --git a/libs/binder/IInterface.cpp b/libs/binder/IInterface.cpp
index 2fcd3d9..6b77291 100644
--- a/libs/binder/IInterface.cpp
+++ b/libs/binder/IInterface.cpp
@@ -32,14 +32,14 @@
 // static
 sp<IBinder> IInterface::asBinder(const IInterface* iface)
 {
-    if (iface == NULL) return NULL;
+    if (iface == nullptr) return nullptr;
     return const_cast<IInterface*>(iface)->onAsBinder();
 }
 
 // static
 sp<IBinder> IInterface::asBinder(const sp<IInterface>& iface)
 {
-    if (iface == NULL) return NULL;
+    if (iface == nullptr) return nullptr;
     return iface->onAsBinder();
 }