io_uring: fix clear IORING_SETUP_R_DISABLED in wrong function

io_uring: fix clear IORING_SETUP_R_DISABLED in wrong function

In commit 3ebba796fa25 ("io_uring: ensure that SQPOLL thread is started for exit"),
the IORING_SETUP_R_DISABLED is cleared in io_sq_offload_start(), but when backport
it to stable-5.10, IORING_SETUP_R_DISABLED is cleared in __io_req_task_submit(),
move clearing IORING_SETUP_R_DISABLED to io_sq_offload_start() to fix this.

Fixes: 6cae8095490ca ("io_uring: ensure that SQPOLL thread is started for exit")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>