Replace NULL with nullptr

Also fixed some lines that were too long, and a few other minor
details.

Change-Id: I6efba5fb6e03eb5d0a300fddb2a75bf8e2f175cb
diff --git a/runtime/mirror/art_method.cc b/runtime/mirror/art_method.cc
index 9483ba6..543cf9b 100644
--- a/runtime/mirror/art_method.cc
+++ b/runtime/mirror/art_method.cc
@@ -362,7 +362,7 @@
   Runtime* runtime = Runtime::Current();
   ClassLinker* class_linker = runtime->GetClassLinker();
   const void* code = runtime->GetInstrumentation()->GetQuickCodeFor(this, pointer_size);
-  // On failure, instead of nullptr we get the quick-generic-jni-trampoline for native method
+  // On failure, instead of null we get the quick-generic-jni-trampoline for native method
   // indicating the generic JNI, or the quick-to-interpreter-bridge (but not the trampoline)
   // for non-native methods.
   if (class_linker->IsQuickToInterpreterBridge(code) ||
@@ -503,7 +503,7 @@
 
   const void* entry_point = runtime->GetInstrumentation()->GetQuickCodeFor(this, sizeof(void*));
   ClassLinker* class_linker = runtime->GetClassLinker();
-  // On failure, instead of nullptr we get the quick-generic-jni-trampoline for native method
+  // On failure, instead of null we get the quick-generic-jni-trampoline for native method
   // indicating the generic JNI, or the quick-to-interpreter-bridge (but not the trampoline)
   // for non-native methods. And we really shouldn't see a failure for non-native methods here.
   DCHECK(!class_linker->IsQuickToInterpreterBridge(entry_point));