add fillDescriptions function needed by the HLT : CorrPFMETProducer (80X)

[mmarionncern]

Same as #14830 for 80X

[cmsbuild]

A new Pull Request was created by @mmarionncern for CMSSW_8_0_X.

It involves the following packages:

JetMETCorrections/Type1MET

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@rappoccio, @ahinzmann, @TaiSakuma, @jdolen, @nhanvtran, @schoef, @mariadalfonso this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/13456/console

[cmsbuild]

+1
Tested at: bb5cc21
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14841/13456/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14841/13456/summary.html

[cvuosalo]

+1

For #14841 bb5cc21

Adding fillDescriptions method to CorrectedPFMETProducer. There should be no change in monitored quantities.

#14830 is the 81X version of this PR, and it has already been merged.

The code change is satisfactory, and Jenkins tests against baseline CMSSW_8_0_X_2016-06-07-2300 show no significant differences, as expected.