usb: gadget: f_uac1: stop playback on function disable

stable inclusion
from stable-5.10.24
commit 32ad0eb74eac53766b65ec377c77af10bee765fc
bugzilla: 51348

--------------------------------

commit cc2ac63d upstream.

There is missing playback stop/cleanup in case of
gadget's ->disable callback that happens on
events like USB host resetting or gadget disconnection

Fixes: 0591bc23 ("usb: gadget: add f_uac1 variant based on a new u_audio api")
Cc: <stable@vger.kernel.org> # 4.13+
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Link: https://lore.kernel.org/r/1614599375-8803-3-git-send-email-ruslan.bilovol@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>