[Audio_test]修复Ql_AudPlayer_PlayFrmFile播放完成回调方法不生效的问题

1.修复Ql_AudPlayer_PlayFrmFile播放完成回调方法不生效的问题
2.修复write操作后返回值为-1报错的问题

Change-Id: I2b9695653301e4bbe6f805a359c47c0ce77d1a9c
diff --git a/mbtk/test/audio_test.c b/mbtk/test/audio_test.c
index 3391a84..2a502af 100755
--- a/mbtk/test/audio_test.c
+++ b/mbtk/test/audio_test.c
@@ -143,6 +143,7 @@
                     memset(databuf, 0, sizeof(databuf));
                     while(0 < (size = read(fd, databuf, sizeof(databuf))))
                     {
+                        Ql_Rxgain_Set(2);
                         if(-1 == Ql_AudPlayer_Play(play_hdl, databuf, size))
                             break;
                     }
@@ -161,6 +162,7 @@
 
                 if(0 == MBTK_wav_pcm16Le_check(fd))
                 {
+                    Ql_Rxgain_Set(11);
                     Ql_AudPlayer_PlayFrmFile(play_hdl, fd, 0);
                 }
                 else