sched/headers: Move the sched_exec() prototype to <linux/sched/task.h>

sched_exec() better fits into the task lifetime APIs than into the core scheduler
APIs.

This reduces the size of <linux/sched.h> a bit.

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.h

···
 #define cpu_relax_yield() cpu_relax()
 #endif
 
-/* sched_exec is called by processes performing an exec */
-#ifdef CONFIG_SMP
-extern void sched_exec(void);
-#else
-#define sched_exec()   {}
-#endif
-
 extern int yield_to(struct task_struct *p, bool preempt);
 extern void set_user_nice(struct task_struct *p, long nice);
 extern int task_prio(const struct task_struct *p);

include/linux/sched/task.h

···
 
 extern void free_task(struct task_struct *tsk);
 
+/* sched_exec is called by processes performing an exec */
+#ifdef CONFIG_SMP
+extern void sched_exec(void);
+#else
+#define sched_exec()   {}
+#endif
+
 #define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while(0)
 
 extern void __put_task_struct(struct task_struct *t);