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: Linus Torvalds <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

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
···
 	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
···
 	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)
 {
···
  */
 #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;
···
 				 void __user *buffer, size_t *lenp,
 				 loff_t *ppos);
 
-#endif /* _SCHED_SYSCTL_H */
+#endif /* _LINUX_SCHED_SYSCTL_H */