Documentation: remove duplicated words

Remove many duplicated words under Documentation/ and do other small
cleanups.

Examples:
        "and and" --> "and"
        "in in" --> "in"
        "the the" --> "the"
        "the the" --> "to the"
        ...

Signed-off-by: Paolo Ornati <ornati@fastwebnet.it>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

Documentation/networking/cs89x0.txt

@@ -684,7 +684,7 @@ ethernet@crystal.cirrus.com) and request that you be registered for automatic
 software-update notification.
 
 Cirrus Logic maintains a web page at http://www.cirrus.com with the
-the latest drivers and technical publications.
+latest drivers and technical publications.
 
 
 6.4 Current maintainer