CQ should only wipe CR on the patchset it tested.
CQ should only wipe CR on the patchset it tested.

For instances where someone is on the ball and spots that CQ will fail
and remove the CR from their patch, the dev may upload a fix already,
or do the necessary rebasing and level a CR on the new patchset.

CQ however still would wipe all CR scoring; as such, wipe it for
just the patchset that has it set.

BUG=None
TEST=run_tests.sh, although it doesn't cover this.

Change-Id: I065afaaa271694de9c19d6538288a9a1bfebfe31
Reviewed-on: https://gerrit.chromium.org/gerrit/15554
Tested-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Chris Sosa <959d3d631fb6f17f1b07f751372041a1edb210d1@chromium.org>
Commit-Ready: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>

coreos/chromite,chadversary/chromiumos.chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,zhang0137/chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,zhang0137/chromite