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/blackfin/bfin-gpio-notes.txt b/Documentation/blackfin/bfin-gpio-notes.txt
index 9898c7de..f731c1e 100644
--- a/Documentation/blackfin/bfin-gpio-notes.txt
+++ b/Documentation/blackfin/bfin-gpio-notes.txt
@@ -43,7 +43,7 @@
 	void bfin_gpio_irq_free(unsigned gpio);
 
     The request functions will record the function state for a certain pin,
-    the free functions will clear it's function state.
+    the free functions will clear its function state.
     Once a pin is requested, it can't be requested again before it is freed by
     previous caller, otherwise kernel will dump stacks, and the request
     function fail.