The comment for fcp_avc_transaction() describes it doesn't support this type
of operation. But it was already supported by this commit.

00a7bb81
ALSA: firewire-lib: Add support for deferred transaction
Signed-off-by: NTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>