sched, futex: detach sched.h and futex.h

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/futex.h b/include/linux/futex.h
index 92d420f..1a15f8e 100644
--- a/include/linux/futex.h
+++ b/include/linux/futex.h
@@ -1,8 +1,12 @@
 #ifndef _LINUX_FUTEX_H
 #define _LINUX_FUTEX_H
 
-#include <linux/sched.h>
+#include <linux/compiler.h>
+#include <linux/types.h>
 
+struct inode;
+struct mm_struct;
+struct task_struct;
 union ktime;
 
 /* Second argument to futex syscall */