ac3dec: change logging of skipped E-AC-3 substreams.

Change log level from warning to debug: the E-AC-3 "core"
substream can be successfully decoded without the additional
and dependent substreams, and their presence is already
indicated via avpriv_request_sample in ff_eac3_parse_header.
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/ac3dec.c

@@ -1347,8 +1347,9 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data,
             /* skip frame if CRC is ok. otherwise use error concealment. */
             /* TODO: add support for substreams and dependent frames */
             if (s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
-                av_log(avctx, AV_LOG_WARNING, "unsupported frame type : "
-                       "skipping frame\n");
+                av_log(avctx, AV_LOG_DEBUG,
+                       "unsupported frame type %d: skipping frame\n",
+                       s->frame_type);
                 *got_frame_ptr = 0;
                 return buf_size;
             } else {