signal: break out of wait loops on kthread_stop() Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> ...org/r/20220627120020.608117-1-Jason@zx2c4.com ...org/r/20220627145716.641185-1-Jason@zx2c4.com ...org/r/20220628161441.892925-1-Jason@zx2c4.com ...kernel.org/r/20220711202136.64458-1-Jason@zx2c4.com ...org/r/20220711232123.136330-1-Jason@zx2c4.com