sched: proper prototype for kernel/sched.c:migration_init()

This patch adds a proper prototype for migration_init() in
include/linux/sched.h

Since there's no point in always returning 0 to a caller that doesn't check
the return value it also changes the function to return void.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/init/main.c b/init/main.c
index f605a96..80b04b6 100644
--- a/init/main.c
+++ b/init/main.c
@@ -56,6 +56,7 @@
 #include <linux/pid_namespace.h>
 #include <linux/device.h>
 #include <linux/kthread.h>
+#include <linux/sched.h>
 
 #include <asm/io.h>
 #include <asm/bugs.h>
@@ -747,11 +748,8 @@
 static void __init do_pre_smp_initcalls(void)
 {
 	extern int spawn_ksoftirqd(void);
-#ifdef CONFIG_SMP
-	extern int migration_init(void);
 
 	migration_init();
-#endif
 	spawn_ksoftirqd();
 	if (!nosoftlockup)
 		spawn_softlockup_task();