avcodec/bfi: Provide non NULL context to av_log()

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/bfi.c

@@ -71,7 +71,7 @@ static int bfi_decode_frame(AVCodecContext *avctx, void *data,
         frame->key_frame = 1;
         /* Setting the palette */
         if (avctx->extradata_size > 768) {
-            av_log(NULL, AV_LOG_ERROR, "Palette is too large.\n");
+            av_log(avctx, AV_LOG_ERROR, "Palette is too large.\n");
             return AVERROR_INVALIDDATA;
         }
         pal = (uint32_t *)frame->data[1];