alac: remove redundant "alac: " from log messages

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/alac.c

@@ -601,12 +601,12 @@ static av_cold int alac_decode_init(AVCodecContext * avctx)
 
     /* initialize from the extradata */
     if (alac->avctx->extradata_size != ALAC_EXTRADATA_SIZE) {
-        av_log(avctx, AV_LOG_ERROR, "alac: expected %d extradata bytes\n",
+        av_log(avctx, AV_LOG_ERROR, "expected %d extradata bytes\n",
             ALAC_EXTRADATA_SIZE);
         return -1;
     }
     if (alac_set_info(alac)) {
-        av_log(avctx, AV_LOG_ERROR, "alac: set_info failed\n");
+        av_log(avctx, AV_LOG_ERROR, "set_info failed\n");
         return -1;
     }