exr: add CODEC_CAP_DR1

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

libavcodec/exr.c

@@ -491,5 +491,6 @@ AVCodec ff_exr_decoder = {
     .init               = decode_init,
     .close              = decode_end,
     .decode             = decode_frame,
+    .capabilities       = CODEC_CAP_DR1,
     .long_name          = NULL_IF_CONFIG_SMALL("OpenEXR image"),
 };