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>
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index e2f7dc6..34bf8f6 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -135,7 +135,7 @@
 		Sets two variables that limit the size of the request.
 
 		- The request queue's max_sectors, which is a soft size in
-		in units of 512 byte sectors, and could be dynamically varied
+		units of 512 byte sectors, and could be dynamically varied
 		by the core kernel.
 
 		- The request queue's max_hw_sectors, which is a hard limit