Documentation: Fix multiple typo in Documentation

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/device-mapper/persistent-data.txt b/Documentation/device-mapper/persistent-data.txt
index 0e5df9b..a333bcb 100644
--- a/Documentation/device-mapper/persistent-data.txt
+++ b/Documentation/device-mapper/persistent-data.txt
@@ -3,7 +3,7 @@
 
 The more-sophisticated device-mapper targets require complex metadata
 that is managed in kernel.  In late 2010 we were seeing that various
-different targets were rolling their own data strutures, for example:
+different targets were rolling their own data structures, for example:
 
 - Mikulas Patocka's multisnap implementation
 - Heinz Mauelshagen's thin provisioning target