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/atomic_ops.txt b/Documentation/atomic_ops.txt
index 396bec3..ac4d471 100644
--- a/Documentation/atomic_ops.txt
+++ b/Documentation/atomic_ops.txt
@@ -320,7 +320,7 @@
 obj->active update does.
 
 As a historical note, 32-bit Sparc used to only allow usage of
-24-bits of it's atomic_t type.  This was because it used 8 bits
+24-bits of its atomic_t type.  This was because it used 8 bits
 as a spinlock for SMP safety.  Sparc32 lacked a "compare and swap"
 type instruction.  However, 32-bit Sparc has since been moved over
 to a "hash table of spinlocks" scheme, that allows the full 32-bit