exr: use buf_size instead of recalculating same value

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 6388794b2b..113eb88082 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -173,7 +173,7 @@ static int decode_frame(AVCodecContext *avctx,
     s->channel_offsets[3] = -1;
     s->bits_per_color_id = -1;
 
-    if (buf_end - buf < 10) {
+    if (buf_size < 10) {
         av_log(avctx, AV_LOG_ERROR, "Too short header to parse\n");
         return -1;
     }