binder: Return pid_t/uid_t instead of int

Makes IPCThreadState::getCalling{Pid,Uid} return a more
appropriate type.

Change-Id: I97f8a83c1c0722bc1afbf8a6df1a288f8f1f0d2c
diff --git a/include/binder/IPCThreadState.h b/include/binder/IPCThreadState.h
index b29c266..60c2242 100644
--- a/include/binder/IPCThreadState.h
+++ b/include/binder/IPCThreadState.h
@@ -39,8 +39,8 @@
             
             status_t            clearLastError();
 
-            int                 getCallingPid() const;
-            int                 getCallingUid() const;
+            pid_t               getCallingPid() const;
+            uid_t               getCallingUid() const;
 
             void                setStrictModePolicy(int32_t policy);
             int32_t             getStrictModePolicy() const;