powerpc: Convert old cpumask API into new one

Adapt new API.

Almost change is trivial. Most important change is the below line
because we plan to change task->cpus_allowed implementation.

-       ctx->cpus_allowed = current->cpus_allowed;

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4a6a109..06b9d45 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -221,7 +221,7 @@
 	}
 
 #ifdef CONFIG_KEXEC
-	cpu_set(smp_processor_id(), cpus_in_sr);
+	cpumask_set_cpu(smp_processor_id(), &cpus_in_sr);
 #endif
 
 	die("System Reset", regs, SIGABRT);