Documentation: fix common spelling mistakes

This fixes several spelling mistakes in the Documentation/ tree, which
are caught by checkpatch.pl's spell checking.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/filesystems/pohmelfs/design_notes.txt b/Documentation/filesystems/pohmelfs/design_notes.txt
index 8aef9133..106d17f 100644
--- a/Documentation/filesystems/pohmelfs/design_notes.txt
+++ b/Documentation/filesystems/pohmelfs/design_notes.txt
@@ -29,7 +29,7 @@
  * Read request (data read, directory listing, lookup requests) balancing between multiple servers.
  * Write requests are replicated to multiple servers and completed only when all of them are acked.
  * Ability to add and/or remove servers from the working set at run-time.
- * Strong authentification and possible data encryption in network channel.
+ * Strong authentication and possible data encryption in network channel.
  * Extended attributes support.
 
 POHMELFS is based on transactions, which are potentially long-standing objects that live