ALSA: fireface: remove unnecessary condition in hwdep_read()

Smatch complains that "count" is not clamped when "ff->dev_lock_changed"
and it leads to an information leak.  Fortunately, that's not actually
possible and the condition can be deleted.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/YA6n6I8EcNAO5ZFs@mwanda
Signed-off-by: Takashi Iwai <tiwai@suse.de>