Replace NULL macros with nullptr literals.

Change-Id: Id2311cda59dd42c74b3ed54d3ff6cfd509012738
diff --git a/lib/Renderscript/RSEmbedInfo.cpp b/lib/Renderscript/RSEmbedInfo.cpp
index b19519f..06fe547 100644
--- a/lib/Renderscript/RSEmbedInfo.cpp
+++ b/lib/Renderscript/RSEmbedInfo.cpp
@@ -54,7 +54,7 @@
 public:
   RSEmbedInfoPass()
       : ModulePass(ID),
-        M(NULL) {
+        M(nullptr) {
   }
 
   static std::string getRSInfoString(const llvm::Module *module) {