s390/smp: __smp_rescan_cpus() - move cpumask away from stack

Avoid a potentially large stack frame and overflow by making
"cpumask_t avail" a static variable. There is no concurrent
access due to the existing locking.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/kernel/smp.c

@@ -775,7 +775,7 @@ static int smp_add_core(struct sclp_core_entry *core, cpumask_t *avail,
 static int __smp_rescan_cpus(struct sclp_core_info *info, bool early)
 {
 	struct sclp_core_entry *core;
-	cpumask_t avail;
+	static cpumask_t avail;
 	bool configured;
 	u16 core_id;
 	int nr, i;