s390/early: Add __init to __do_early_pgm_check()

__do_early_pgm_check() is a function which is only needed during early
setup code. Mark it __init in order to save a few bytes.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/kernel/early.c

@@ -175,7 +175,7 @@ static __init void setup_topology(void)
 	topology_max_mnest = max_mnest;
 }
 
-void __do_early_pgm_check(struct pt_regs *regs)
+void __init __do_early_pgm_check(struct pt_regs *regs)
 {
 	struct lowcore *lc = get_lowcore();
 	unsigned long ip;