enter_from_user_mode_randomize_stack() replaces enter_from_user_mode() and
the subsequent invocation of add_random_kstack_offset_irqsoff().

As a bonus this avoids the overhead of get/put_cpu_var() in
add_random_kstack_offset().

No functional change.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
---
 arch/s390/kernel/syscall.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/s390/kernel/syscall.c
+++ b/arch/s390/kernel/syscall.c

@@ -97,8 +97,8 @@ void noinstr __do_syscall(struct pt_regs
 {
 	unsigned long nr;
 
-	enter_from_user_mode(regs);
-	add_random_kstack_offset();
+	enter_from_user_mode_randomize_stack(regs);
+
 	regs->psw = get_lowcore()->svc_old_psw;
 	regs->int_code = get_lowcore()->svc_int_code;
 	update_timer_sys();