dm log: make dm_dirty_log init and exit static

dm_dirty_log_{init,exit}() can now become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm.h

@@ -100,12 +100,6 @@ int dm_lock_for_deletion(struct mapped_device *md);
 
 void dm_kobject_uevent(struct mapped_device *md);
 
-/*
- * Dirty log
- */
-int dm_dirty_log_init(void);
-void dm_dirty_log_exit(void);
-
 int dm_kcopyd_init(void);
 void dm_kcopyd_exit(void);