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/s390/s390dbf.txt b/Documentation/s390/s390dbf.txt
index 389e0e5..000230c 100644
--- a/Documentation/s390/s390dbf.txt
+++ b/Documentation/s390/s390dbf.txt
@@ -65,7 +65,7 @@
 It is also possible to define other views. The content of
 a view can be inspected simply by reading the corresponding debugfs file.
 
-All debug logs have an an actual debug level (range from 0 to 6).
+All debug logs have an actual debug level (range from 0 to 6).
 The default level is 3. Event and Exception functions have a 'level'
 parameter. Only debug entries with a level that is lower or equal
 than the actual level are written to the log. This means, when
@@ -556,7 +556,7 @@
 the view (e.g. like with 'echo "0" > /sys/kernel/debug/s390dbf/dasd/level).
 
 For header_proc there can be used the default function
-debug_dflt_header_fn() which is defined in in debug.h.
+debug_dflt_header_fn() which is defined in debug.h.
 and which produces the same header output as the predefined views.
 E.g:
 00 00964419409:440761 2 - 00 88023ec