Do not log error codes received from HAL

audio HAL server already logs them, so logging them here is just
a spam. Only log RPC errors.

Change-Id: I55433d4446215b87099c9ad33f4c352f79109fd1
Test: check logcat
diff --git a/media/libaudiohal/ConversionHelperHidl.cpp b/media/libaudiohal/ConversionHelperHidl.cpp
index ebbc02c..3451eb0 100644
--- a/media/libaudiohal/ConversionHelperHidl.cpp
+++ b/media/libaudiohal/ConversionHelperHidl.cpp
@@ -91,8 +91,8 @@
 status_t ConversionHelperHidl::processReturn(
         const char* funcName, const Status& status, hardware::audio::V2_0::Result retval) {
     const status_t st = status.isOk() ? analyzeResult(retval) : status.transactionError();
-    ALOGE_IF(st, "%s %p %s: %s (from %s)",
-            mClassName, this, funcName, strerror(-st), status.isOk() ? "hal" : "rpc");
+    ALOGE_IF(!status.isOk() && st, "%s %p %s: %s (from rpc)",
+            mClassName, this, funcName, strerror(-st));
     return st;
 }