avcodec/adpcm: Fix overflow in FFABS() IMA_EA_EACS

Fixes: negation of -2147483648 cannot be represented in type 'int'; cast to an unsigned type to negate this value to itself
Fixes: 19235/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_IMA_EA_EACS_fuzzer-5680878952382464

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

libavcodec/adpcm.c

@@ -1233,7 +1233,7 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
         }
         for (i=0; i<=st; i++) {
             c->status[i].predictor  = bytestream2_get_le32u(&gb);
-            if (FFABS(c->status[i].predictor) > (1<<16))
+            if (FFABS((int64_t)c->status[i].predictor) > (1<<16))
                 return AVERROR_INVALIDDATA;
         }