sched/headers: Make all include/linux/sched/*.h headers build standalone

Make each header self-sufficient, so that it can be built successfully
both in an allnoconfig and allyesconfig kernel.

Also standardize the naming of their header guards.
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

include/linux/sched/deadline.h

-#ifndef _SCHED_DEADLINE_H
-#define _SCHED_DEADLINE_H
+#ifndef _LINUX_SCHED_DEADLINE_H
+#define _LINUX_SCHED_DEADLINE_H
+
+#include <linux/sched.h>
 
 /*
  * SCHED_DEADLINE tasks has negative priorities, reflecting
@@ -26,4 +28,4 @@ static inline bool dl_time_before(u64 a, u64 b)
 	return (s64)(a - b) < 0;
 }
 
-#endif /* _SCHED_DEADLINE_H */
+#endif /* _LINUX_SCHED_DEADLINE_H */

include/linux/sched/prio.h

-#ifndef _SCHED_PRIO_H
-#define _SCHED_PRIO_H
+#ifndef _LINUX_SCHED_PRIO_H
+#define _LINUX_SCHED_PRIO_H
 
 #define MAX_NICE	19
 #define MIN_NICE	-20
@@ -57,4 +57,4 @@ static inline long rlimit_to_nice(long prio)
 	return (MAX_NICE - prio + 1);
 }
 
-#endif /* _SCHED_PRIO_H */
+#endif /* _LINUX_SCHED_PRIO_H */

include/linux/sched/rt.h

-#ifndef _SCHED_RT_H
-#define _SCHED_RT_H
+#ifndef _LINUX_SCHED_RT_H
+#define _LINUX_SCHED_RT_H
 
-#include <linux/sched/prio.h>
+#include <linux/sched.h>
+
+struct task_struct;
 
 static inline int rt_prio(int prio)
 {
@@ -57,4 +59,4 @@ extern void normalize_rt_tasks(void);
  */
 #define RR_TIMESLICE		(100 * HZ / 1000)
 
-#endif /* _SCHED_RT_H */
+#endif /* _LINUX_SCHED_RT_H */

include/linux/sched/sysctl.h

-#ifndef _SCHED_SYSCTL_H
-#define _SCHED_SYSCTL_H
+#ifndef _LINUX_SCHED_SYSCTL_H
+#define _LINUX_SCHED_SYSCTL_H
+
+#include <linux/types.h>
+
+struct ctl_table;
 
 #ifdef CONFIG_DETECT_HUNG_TASK
 extern int	     sysctl_hung_task_check_count;
@@ -78,4 +82,4 @@ extern int sysctl_schedstats(struct ctl_table *table, int write,
 				 void __user *buffer, size_t *lenp,
 				 loff_t *ppos);
 
-#endif /* _SCHED_SYSCTL_H */
+#endif /* _LINUX_SCHED_SYSCTL_H */