media.log cleanup

Remove almost all of the specific logs, but leave the media.log
logging infrastructure in place for the next time we need it.

Re-apply a few good changes that were reverted earlier:
 - check logf format vs. argument list compatibility
 - distinguish potentially modified and actually modified tracks in FastMixer
 - fix benign bug where sq->end() was called more than once
 - fix a build warning

Bug: 6490974
Change-Id: I02d3e83646c738acaebb415bd0d6b548638b4ef5
diff --git a/services/audioflinger/AudioMixer.h b/services/audioflinger/AudioMixer.h
index fd21fda..43aeb86 100644
--- a/services/audioflinger/AudioMixer.h
+++ b/services/audioflinger/AudioMixer.h
@@ -28,6 +28,7 @@
 
 #include <audio_effects/effect_downmix.h>
 #include <system/audio.h>
+#include <media/nbaio/NBLog.h>
 
 namespace android {
 
@@ -220,7 +221,8 @@
         void            (*hook)(state_t* state, int64_t pts);   // one of process__*, never NULL
         int32_t         *outputTemp;
         int32_t         *resampleTemp;
-        int32_t         reserved[2];
+        NBLog::Writer*  mLog;
+        int32_t         reserved[1];
         // FIXME allocate dynamically to save some memory when maxNumTracks < MAX_NUM_TRACKS
         track_t         tracks[MAX_NUM_TRACKS]; __attribute__((aligned(32)));
     };
@@ -247,6 +249,10 @@
 
     const uint32_t  mSampleRate;
 
+    NBLog::Writer   mDummyLog;
+public:
+    void            setLog(NBLog::Writer* log);
+private:
     state_t         mState __attribute__((aligned(32)));
 
     // effect descriptor for the downmixer used by the mixer