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/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 8633691..2043d54 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -350,12 +350,12 @@
     return err;
 }
 
-int IPCThreadState::getCallingPid() const
+pid_t IPCThreadState::getCallingPid() const
 {
     return mCallingPid;
 }
 
-int IPCThreadState::getCallingUid() const
+uid_t IPCThreadState::getCallingUid() const
 {
     return mCallingUid;
 }