dm table: remove unused dm_get_device range parameters

Remove unused parameters(start and len) of dm_get_device()
and fix the callers.

Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
index 7035582..5a08be0 100644
--- a/drivers/md/dm-log.c
+++ b/drivers/md/dm-log.c
@@ -543,8 +543,7 @@
 		return -EINVAL;
 	}
 
-	r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
-			  FMODE_READ | FMODE_WRITE, &dev);
+	r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &dev);
 	if (r)
 		return r;