softlockup: fix signedness

fix softlockup tunables signedness.

mark tunables read-mostly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dfc76e1..53534f9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -269,10 +269,10 @@
 extern void spawn_softlockup_task(void);
 extern void touch_softlockup_watchdog(void);
 extern void touch_all_softlockup_watchdogs(void);
-extern int softlockup_thresh;
+extern unsigned long  softlockup_thresh;
 extern unsigned long sysctl_hung_task_check_count;
 extern unsigned long sysctl_hung_task_timeout_secs;
-extern long sysctl_hung_task_warnings;
+extern unsigned long sysctl_hung_task_warnings;
 #else
 static inline void softlockup_tick(void)
 {