hqx: Merge invalid format check within switch block

libavcodec/hqx.c

@@ -573,8 +573,7 @@ static int hqx_decode_frame(AVCodecContext *avctx, void *data,
         avctx->pix_fmt = AV_PIX_FMT_YUVA444P16;
         decode_func = hqx_decode_444a;
         break;
-    }
-    if (!decode_func) {
+    default:
         av_log(avctx, AV_LOG_ERROR, "Invalid format: %d.\n", ctx->format);
         return AVERROR_INVALIDDATA;
     }