md: Fix typo in drivers/md

Correct spelling typo in drivers/md.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/md/persistent-data/dm-btree.h b/drivers/md/persistent-data/dm-btree.h
index ae02c84..a2cd5044 100644
--- a/drivers/md/persistent-data/dm-btree.h
+++ b/drivers/md/persistent-data/dm-btree.h
@@ -35,7 +35,7 @@
  */
 
 /*
- * Infomation about the values stored within the btree.
+ * Information about the values stored within the btree.
  */
 struct dm_btree_value_type {
 	void *context;