[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/Debug.cpp b/libs/binder/Debug.cpp
index 4ac61a3..f38bbb2 100644
--- a/libs/binder/Debug.cpp
+++ b/libs/binder/Debug.cpp
@@ -165,13 +165,13 @@
         else if (bytesPerLine >= 8) alignment = 2;
         else alignment = 1;
     }
-    if (func == NULL) func = defaultPrintFunc;
+    if (func == nullptr) func = defaultPrintFunc;
 
     size_t offset;
 
     unsigned char *pos = (unsigned char *)buf;
 
-    if (pos == NULL) {
+    if (pos == nullptr) {
         if (singleLineBytesCutoff < 0) func(cookie, "\n");
         func(cookie, "(NULL)");
         return;
@@ -297,7 +297,7 @@
 
 ssize_t getBinderKernelReferences(size_t count, uintptr_t* buf) {
     sp<ProcessState> proc = ProcessState::selfOrNull();
-    if (proc.get() == NULL) {
+    if (proc.get() == nullptr) {
         return 0;
     }