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>

Documentation/filesystems/proc.txt

@@ -965,7 +965,7 @@ your system and how much traffic was routed over those devices:
   ...] 1375103    17405    0    0    0     0       0          0 
   ...] 1703981     5535    0    0    0     3       0          0 
 
-In addition, each Channel Bond interface has it's own directory.  For
+In addition, each Channel Bond interface has its own directory.  For
 example, the bond0 device will have a directory called /proc/net/bond0/.
 It will contain information that is specific to that bond, such as the
 current slaves of the bond, the link status of the slaves, and how
@@ -1362,7 +1362,7 @@ been accounted as having caused 1MB of write.
 In other words: The number of bytes which this process caused to not happen,
 by truncating pagecache. A task can cause "negative" IO too. If this task
 truncates some dirty pagecache, some IO which another task has been accounted
-for (in it's write_bytes) will not be happening. We _could_ just subtract that
+for (in its write_bytes) will not be happening. We _could_ just subtract that
 from the truncating task's write_bytes, but there is information loss in doing
 that.