avcodec/loco: Check left column value

Fixes: Timeout (42sec -> 379 ms)
Fixes: 16323/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LOCO_fuzzer-5679178099195904

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpegReviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/loco.c

@@ -161,6 +161,8 @@ static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int heigh
     for (j = 1; j < height; j++) {
         /* restore left column */
         val = loco_get_rice(&rc);
+        if (val == INT_MIN)
+           return AVERROR_INVALIDDATA;
         data[0] = data[-stride] + val;
         /* restore all other pixels */
         for (i = 1; i < width; i++) {