Fix warning in audio policy service

Change-Id: I33b20b7007e19e8b2514ffdf2232e9c1d7314d9f
diff --git a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
index 02603b8..c9b3abc 100644
--- a/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
+++ b/services/audiopolicy/service/AudioPolicyInterfaceImpl.cpp
@@ -287,7 +287,7 @@
     bool updatePid = (pid == -1);
     const uid_t callingUid = IPCThreadState::self()->getCallingUid();
     if (!isTrustedCallingUid(callingUid)) {
-        ALOGW_IF(uid != -1 && uid != (int)callingUid,
+        ALOGW_IF(uid != (uid_t)-1 && uid != callingUid,
                 "%s uid %d tried to pass itself off as %d", __FUNCTION__, callingUid, uid);
         uid = callingUid;
         updatePid = true;
@@ -295,7 +295,7 @@
 
     if (updatePid) {
         const pid_t callingPid = IPCThreadState::self()->getCallingPid();
-        ALOGW_IF(pid != -1 && pid != callingPid,
+        ALOGW_IF(pid != (pid_t)-1 && pid != callingPid,
                  "%s uid %d pid %d tried to pass itself off as pid %d",
                  __func__, callingUid, callingPid, pid);
         pid = callingPid;