io_uring_sanitise_params() already rejects flags that include both
IORING_SETUP_SQPOLL and IORING_SETUP_DEFER_TASKRUN. So it's unnecessary
to check IORING_SETUP_SQPOLL in io_uring_create() when
IORING_SETUP_DEFER_TASKRUN has already been checked. Drop the
!(ctx->flags & IORING_SETUP_SQPOLL) check for the task_complete case.