s390/irq: inline do_softirq_own_stack()

Move do_softirq_own_stack() to proper header file so it can be
inlined; saving a few cycles.

Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2 files changed