Otherwise we could have not negotiated errors in audiomixer when
the channel/channel-mask do not match
Differential Revision: https://phabricator.freedesktop.org/D493
Reviewed-by: Mathieu Duponchelle <mathieu.duponchelle@opencreed.com>
Unref pads_info hash table in dispose instead of
finalize, i.e. before gst_bin_dispose runs and
destroys pads_info->bin (to which the pads_info
does not hold a ref).