ALSA: fireworks: ensure to release isochronous resources in pcm.hw_params callback

When stopping packet streaming in reserve function for duplex streams,
isochronous resources should be released.

Fixes: 7bc93821

 ("ALSA: firewire-lib: split allocation of isochronous resources from establishment of connection")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>