Zlib patch: prevent uninitialized use of state->check

No need to call the Adler32 checksum function, just set
the struct field to the expected value.

Plus some cleanup in the README file (the idea is that this 
file won't be touched for new patches).

Upstream bug: madler/zlib#245

Bug: 697481
Change-Id: Ic495c92c9ca1b5ab8a4d23a8ae29141f4617c091
Reviewed-on: https://chromium-review.googlesource.com/688501
Reviewed-by: Chris Blume <cblume@chromium.org>
Commit-Queue: Chris Blume <cblume@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#504897}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ee376c65abdd5afe787bfb63af9f2e82fdc35c2e
3 files changed