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/arch/arm/fault_handler_arm.cc b/runtime/arch/arm/fault_handler_arm.cc
index 3e8b367..d84cb53 100644
--- a/runtime/arch/arm/fault_handler_arm.cc
+++ b/runtime/arch/arm/fault_handler_arm.cc
@@ -56,7 +56,7 @@
   struct ucontext *uc = reinterpret_cast<struct ucontext*>(context);
   struct sigcontext *sc = reinterpret_cast<struct sigcontext*>(&uc->uc_mcontext);
   Thread* self = Thread::Current();
-  CHECK(self != nullptr);       // This will cause a SIGABRT if self is nullptr.
+  CHECK(self != nullptr);  // This will cause a SIGABRT if self is null.
 
   sc->arm_r0 = reinterpret_cast<uintptr_t>(*self->GetNestedSignalState());
   sc->arm_r1 = 1;