Remove bit fields to improve performance

uint16_t enabled is (mostly) changed to bool in a separate CL

Change-Id: Ied9f8c034b2479cee9a8778cee7b8ff92ae75b7b
diff --git a/services/audioflinger/AudioMixer.cpp b/services/audioflinger/AudioMixer.cpp
index f3bf953..020d62a 100644
--- a/services/audioflinger/AudioMixer.cpp
+++ b/services/audioflinger/AudioMixer.cpp
@@ -257,6 +257,7 @@
             }
             break;
         case AUXLEVEL:
+            //assert(0 <= valueInt && valueInt <= MAX_GAIN_INT);
             if (track.auxLevel != valueInt) {
                 ALOGV("setParameter(VOLUME, AUXLEVEL: %04x)", valueInt);
                 track.prevAuxLevel = track.auxLevel << 16;
@@ -565,7 +566,7 @@
     const int16_t vr = t->volume[1];
 
     if (CC_UNLIKELY(aux != NULL)) {
-        const int16_t va = (int16_t)t->auxLevel;
+        const int16_t va = t->auxLevel;
         do {
             int16_t l = (int16_t)(*temp++ >> 12);
             int16_t r = (int16_t)(*temp++ >> 12);