Fix typos in Documentation/: 'H'-'M'

This patch fixes typos in various Documentation txts. The patch addresses
some words starting with the letters 'H'-'M'.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 5745090..693ef0c 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -715,7 +715,7 @@
 KERNEL SERVICES
 ===============
 
-The kernel services for key managment are fairly simple to deal with. They can
+The kernel services for key management are fairly simple to deal with. They can
 be broken down into two areas: keys and key types.
 
 Dealing with keys is fairly straightforward. Firstly, the kernel service