ALSA: core: remove redundant spin_lock pair in snd_card_disconnect

[ Upstream commit abc21649b3e5c34b143bf86f0c78e33d5815e250 ]

modification in commit 2a3f7221acdd ("ALSA: core: Fix card races between
register and disconnect") resulting in this problem.

Fixes: 2a3f7221acdd ("ALSA: core: Fix card races between register and disconnect")
Signed-off-by: Jia Zhou <zhou.jia2@zte.com.cn>
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Link: https://lore.kernel.org/r/1616989007-34429-1-git-send-email-wang.yi59@zte.com.cn


Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>