Move control block mName to createTrack() output

This is part of a series of CLs to clean up the shared memory
control block, by removing any fields that don't have to be there.

Change-Id: I6e51003a1293b6800258c31b22cff2eba42162e7
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index d510641..1ae51ca 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -436,6 +436,7 @@
         audio_io_handle_t output,
         pid_t tid,
         int *sessionId,
+        String8& name,
         status_t *status)
 {
     sp<PlaybackThread::Track> track;
@@ -524,6 +525,9 @@
         }
     }
     if (lStatus == NO_ERROR) {
+        // s for server's pid, n for normal mixer name, f for fast index
+        name = String8::format("s:%d;n:%d;f:%d", getpid_cached, track->name() - AudioMixer::TRACK0,
+                track->fastIndex());
         trackHandle = new TrackHandle(track);
     } else {
         // remove local strong reference to Client before deleting the Track so that the Client