Fix typos in /Documentation : Misc

This patch fixes typos in various Documentation txts. The patch addresses some
misc words.

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 3da586b..60c665d 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -304,7 +304,7 @@
 	R	Revoked
 	D	Dead
 	Q	Contributes to user's quota
-	U	Under contruction by callback to userspace
+	U	Under construction by callback to userspace
 	N	Negative key
 
      This file must be enabled at kernel configuration time as it allows anyone