Remove unused struct proc_dir_entry::set

After /proc/sys rewrite it was left unused.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/proc_fs.h

@@ -75,7 +75,6 @@ struct proc_dir_entry {
 	write_proc_t *write_proc;
 	atomic_t count;		/* use count */
 	int deleted;		/* delete flag */
-	void *set;
 	int pde_users;	/* number of callers into module in progress */
 	spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
 	struct completion *pde_unload_completion;