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/scsi/st.txt b/Documentation/scsi/st.txt
index 66ba3ad..5ff65b1 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -249,7 +249,7 @@
 
 If the driver is compiled into the kernel, the same parameters can be
 also set using, e.g., the LILO command line. The preferred syntax is
-is to use the same keyword used when loading as module but prepended
+to use the same keyword used when loading as module but prepended
 with 'st.'. For instance, to set the maximum number of scatter/gather
 segments, the parameter 'st.max_sg_segs=xx' should be used (xx is the
 number of scatter/gather segments).