s390/irq: select HAVE_IRQ_EXIT_ON_IRQ_STACK

[ Upstream commit 9ceed9988a8e6a1656ed2bdaa30501cf0f3dd925 ]

irq_exit() is always called on async stack. Therefore select
HAVE_IRQ_EXIT_ON_IRQ_STACK and get a tiny optimization in
invoke_softirq().

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
1 file changed