[S390] Fix build failure in __cpu_up()

The first argument to __ctl_store() should be the array to store
stuff in, not just the first element of that array. With the
current code in __cpu_up(), mainline GCC dies with an internal
compiler error. I didn't diagnose that further, but just fixed
the kernel bug.

Signed-off-by: Segher Boessenkool <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>
Cc: Heiko Carstens <[e-mail]>

arch/s390/kernel/smp.c

···
 	memset(sf, 0, sizeof(struct stack_frame));
 	sf->gprs[9] = (unsigned long) sf;
 	cpu_lowcore->save_area[15] = (unsigned long) sf;
-	__ctl_store(cpu_lowcore->cregs_save_area[0], 0, 15);
+	__ctl_store(cpu_lowcore->cregs_save_area, 0, 15);
 	asm volatile(
 		"	stam	0,15,0(%0)"
 		: : "a" (&cpu_lowcore->access_regs_save_area) : "memory");