binder: make setRequestingSid(false) work

Before, sid could never be turned from being requested to being
unrequested, but no one called the API.

Test: boot, check SafetyNet logs
Change-Id: I0a6df49fcca8f3f0f54d270f6877a13c90c82ff2
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 96ee295..cb0e08d 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -218,7 +218,7 @@
         if (!e) return; // out of memory
     }
 
-    e->mRequestingSid = true;
+    e->mRequestingSid = requestingSid;
 }
 
 BBinder::~BBinder()