ALSA: seq: remove useless function

The function snd_seq_queue_client_termination() is only called from
the function seq_free_client1(). The function seq_free_client1() calls
the function snd_seq_queue_client_leave() and the function
snd_seq_queue_client_termination() together. Because the function
snd_seq_queue_client_leave() does all things, so the function
snd_seq_queue_client_termination() is a useless function.

Signed-off-by: Yu Hao <yuhaobehappy@gmail.com>
Link: https://lore.kernel.org/r/20201103223335.21831-1-yuhaobehappy@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>