Revert "usb: gadget: ffs: Fix BUG when userland exits with submitted AIO transfers"

Revert "usb: gadget: ffs: Fix BUG when userland exits with submitted AIO transfers"

This reverts commit b4194da3f9087dd38d91b40f9bec42d59ce589a8
since it causes list corruption followed by kernel panic:

Workqueue: adb ffs_aio_cancel_worker
RIP: 0010:__list_add_valid+0x4d/0x70
Call Trace:
insert_work+0x47/0xb0
__queue_work+0xf6/0x400
queue_work_on+0x65/0x70
dwc3_gadget_giveback+0x44/0x50 [dwc3]
dwc3_gadget_ep_dequeue+0x83/0x2d0 [dwc3]
? finish_wait+0x80/0x80
usb_ep_dequeue+0x1e/0x90
process_one_work+0x18c/0x3b0
worker_thread+0x3c/0x390
? process_one_work+0x3b0/0x3b0
kthread+0x11e/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50

This issue is seen with warm reboot stability testing.

Signed-off-by: Shen Jing <jingx.shen@intel.com>
Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>