avcodec/bmp: Use ff_set_dimensions()

Fixes out of memory

Fixes: 1282/clusterfuzz-testcase-minimized-5400131681648640

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 63b8d4146d)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/bmp.c

@@ -133,8 +133,11 @@ static int bmp_decode_frame(AVCodecContext *avctx,
         alpha = bytestream_get_le32(&buf);
     }
 
-    avctx->width  = width;
-    avctx->height = height > 0 ? height : -(unsigned)height;
+    ret = ff_set_dimensions(avctx, width, height > 0 ? height : -(unsigned)height);
+    if (ret < 0) {
+        av_log(avctx, AV_LOG_ERROR, "Failed to set dimensions %d %d\n", width, height);
+        return AVERROR_INVALIDDATA;
+    }
 
     avctx->pix_fmt = AV_PIX_FMT_NONE;