Fix issue 4988574: 8 bit PCM audio playback broken.

Fixed regression in audio track control block frame size
calculation introduced by commit c310dcb.

Change-Id: Ia731b946ae4e43316b98d80229e3b08a696e47d6
diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 482336b..0323fe0 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -2954,7 +2954,7 @@
         mStreamType = streamType;
         // NOTE: audio_track_cblk_t::frameSize for 8 bit PCM data is based on a sample size of
         // 16 bit because data is converted to 16 bit before being stored in buffer by AudioTrack
-        mCblk->frameSize = audio_is_linear_pcm(format) ? mChannelCount * audio_bytes_per_sample(format) : sizeof(uint8_t);
+        mCblk->frameSize = audio_is_linear_pcm(format) ? mChannelCount * sizeof(int16_t) : sizeof(uint8_t);
     }
 }