Documentation/: it's -> its where appropriate

Fix obvious cases of "it's" being used when "its" was meant.

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/dvb/ci.txt b/Documentation/dvb/ci.txt
index 2ecd834..4a0c2b5 100644
--- a/Documentation/dvb/ci.txt
+++ b/Documentation/dvb/ci.txt
@@ -41,7 +41,7 @@
 
 * Cards that fall in this category
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-At present the cards that fall in this category are the Twinhan and it's
+At present the cards that fall in this category are the Twinhan and its
 clones, these cards are available as VVMER, Tomato, Hercules, Orange and
 so on.