DO NOT MERGE: Modify the pseudo-header checksum functions.

- Remove the initial checksum, which we don't use anywhere.
- Add the upper-layer protocol to the IPv6 function. Currently
  this is always the same as the next header field in the IPv6
  header, but technically it's the upper-layer header after all
  the extension headers. This is required to support fragments.

Bug: 11542311
Change-Id: Ie1a20fa74ee5bc933c1014bab74ae2957979b2b8
5 files changed