sysctl: remove "struct file *" argument of ->proc_handler

It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 75cf586..66ebddc 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -110,21 +110,20 @@
 extern unsigned long determine_dirtyable_memory(void);
 
 extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos);
 extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos);
 extern int dirty_ratio_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos);
 extern int dirty_bytes_handler(struct ctl_table *table, int write,
-		struct file *filp, void __user *buffer, size_t *lenp,
+		void __user *buffer, size_t *lenp,
 		loff_t *ppos);
 
 struct ctl_table;
-struct file;
-int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *,
+int dirty_writeback_centisecs_handler(struct ctl_table *, int,
 				      void __user *, size_t *, loff_t *);
 
 void get_dirty_limits(unsigned long *pbackground, unsigned long *pdirty,