dm: publish dm_table_unplug_all

Publish dm_table_unplug_all in include/linux/device-mapper.h because this
function is used by targets.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm.h

@@ -46,7 +46,6 @@ void dm_table_presuspend_targets(struct dm_table *t);
 void dm_table_postsuspend_targets(struct dm_table *t);
 int dm_table_resume_targets(struct dm_table *t);
 int dm_table_any_congested(struct dm_table *t, int bdi_bits);
-void dm_table_unplug_all(struct dm_table *t);
 
 /*
  * To check the return value from dm_table_find_target().

include/linux/device-mapper.h

@@ -237,6 +237,11 @@ int dm_table_add_target(struct dm_table *t, const char *type,
  */
 int dm_table_complete(struct dm_table *t);
 
+/*
+ * Unplug all devices in a table.
+ */
+void dm_table_unplug_all(struct dm_table *t);
+
 /*
  * Table reference counting.
  */