Fix CAS argument type.

Gcc apparently doesn't check; clang does.

Bug:17067219
Change-Id: I184084a5063131dbc857c63f97e70e78a05e1a76
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index d9d4971..2554351 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -144,7 +144,7 @@
 
     if (!e) {
         e = new Extras;
-        uintptr_t* expected = 0;
+        uintptr_t expected = 0;
         if (!atomic_compare_exchange_strong_explicit(
                                         &mExtras, &expected,
                                         reinterpret_cast<uintptr_t>(e),