avformat/cinedec: check av_strdup() return value

Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

libavformat/cinedec.c

@@ -168,6 +168,10 @@ static int cine_read_header(AVFormatContext *avctx)
     avio_skip(pb, 616); // Binning .. bFlipH
     if (!avio_rl32(pb) ^ vflip) {
         st->codecpar->extradata  = av_strdup("BottomUp");
+        if (!st->codecpar->extradata) {
+            st->codecpar->extradata_size = 0;
+            return AVERROR(ENOMEM);
+        }
         st->codecpar->extradata_size  = 9;
     }