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/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt
index 09ab0d2..98f71a5 100644
--- a/Documentation/networking/packet_mmap.txt
+++ b/Documentation/networking/packet_mmap.txt
@@ -100,7 +100,7 @@
 The destruction of the socket and all associated resources
 is done by a simple call to close(fd).
 
-Next I will describe PACKET_MMAP settings and it's constraints,
+Next I will describe PACKET_MMAP settings and its constraints,
 also the mapping of the circular buffer in the user process and 
 the use of this buffer.
 
@@ -432,7 +432,7 @@
                         the PACKET_STATISTICS option.
 
 TP_STATUS_CSUMNOTREADY: currently it's used for outgoing IP packets which 
-                        it's checksum will be done in hardware. So while 
+                        its checksum will be done in hardware. So while
                         reading the packet we should not try to check the 
                         checksum.