avcodec/leaddec: Check init_get_bits8() for failure

Fixes: CID1604416 Unchecked return value

Sponsored-by: Sovereign Tech Fund
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/leaddec.c

@@ -194,7 +194,9 @@ static int lead_decode_frame(AVCodecContext *avctx, AVFrame * frame,
             i++;
     }
 
-    init_get_bits8(&gb, s->bitstream_buf, size);
+    ret = init_get_bits8(&gb, s->bitstream_buf, size);
+    if (ret < 0)
+        return ret;
 
     if (avctx->pix_fmt == AV_PIX_FMT_YUV420P && zero) {
         for (int mb_y = 0; mb_y < avctx->height / 8; mb_y++)