libaom: Dont use aom_codec_av1_dx_algo.

This fixes linking errors where variables cannot be correctly linked in from an external shared library such as with msvc (requires dllimport which is not used by libaom). Instead just call the function that returns the same variable.

Signed-off-by: Matt Oliver <protogonoi@gmail.com>

libavcodec/libaomdec.c

@@ -241,7 +241,7 @@ static av_cold int aom_free(AVCodecContext *avctx)
 
 static av_cold int av1_init(AVCodecContext *avctx)
 {
-    return aom_init(avctx, &aom_codec_av1_dx_algo);
+    return aom_init(avctx, aom_codec_av1_dx());
 }
 
 const AVCodec ff_libaom_av1_decoder = {