include snow encoder only if it is not disabled

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9494 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/snow.c

@@ -4535,7 +4535,7 @@ AVCodec snow_decoder = {
     NULL
 };
 
-#ifdef CONFIG_ENCODERS
+#ifdef CONFIG_SNOW_ENCODER
 AVCodec snow_encoder = {
     "snow",
     CODEC_TYPE_VIDEO,