avopt: Store defaults for AV_OPT_TYPE_INT in the i64 union member

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/gif.c

@@ -355,7 +355,7 @@ static int gif_write_trailer(AVFormatContext *s)
 #define ENC AV_OPT_FLAG_ENCODING_PARAM
 static const AVOption options[] = {
     { "loop", "Number of times to loop the output.", OFFSET(loop),
-      AV_OPT_TYPE_INT, { 0 }, 0, 65535, ENC },
+      AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 65535, ENC },
     { NULL },
 };