fix memory bug in DNN-based ID (packport of #35984)

[slava77]

see details in #35984

I'm proposing a backport to avoid seeing random differences in comparisons due to the two uninitialized variables as seen e.g. in #36089 (comment)

@swagata87

[cmsbuild]

A new Pull Request was created by @slava77 (Slava Krutelyov) for CMSSW_12_1_X.

It involves the following packages:

• RecoEgamma/EgammaElectronProducers (reconstruction)

@jpata, @cmsbuild, @slava77 can you please review it and eventually sign? Thanks.
@Sam-Harper, @jainshilpi, @rovere, @lgray, @sobhatta, @lecriste, @afiqaize, @wrtabb, @varuns23, @ram1123 this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

• Backported from Fixing memory bug in GsfElectronProducer #35984

[slava77]

@cmsbuild please test

[slava77]

backport of #35984

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-3e0eeb/20466/summary.html
COMMIT: 6d8a387
CMSSW: CMSSW_12_1_X_2021-11-11-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/36091/20466/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 48 differences found in the comparisons
• DQMHistoTests: Total files compared: 42
• DQMHistoTests: Total histograms compared: 2901440
• DQMHistoTests: Total failures: 11
• DQMHistoTests: Total nulls: 1
• DQMHistoTests: Total successes: 2901406
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: -0.004 KiB( 41 files compared)
• DQMHistoSizes: changed ( 312.0 ): -0.004 KiB MessageLogger/Warnings
• Checked 177 log files, 37 edm output root files, 42 DQM output files
• TriggerResults: no differences found

[slava77]

+reconstruction

for #36091 6d8a387

• jenkins tests pass and comparisons with the baseline show differences in the electron MVA plots dnn_e_bkgPhoton and dnn_e_bkgTau variables which are now appropriate filled

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_12_1_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_12_2_X is complete. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1