OpenBLAS: Fix parallel compilation option

[smuzaffar]

Internally OpenBLAS ignores the -j N passed to make and use -j $(nproc). Setting MAKE_NB_JOBS=N forces openblas to use N parallel jobs.

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for branch IB/CMSSW_12_1_X/master.

@cmsbuild, @smuzaffar, @iarspider, @mrodozov can you please review it and eventually sign? Thanks.
@perrotta, @dpiparo, @qliphy you are the release manager for this.
cms-bot commands are listed here

[smuzaffar]

please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-2c0f89/19330/summary.html
COMMIT: cf1b03a
CMSSW: CMSSW_12_1_X_2021-10-01-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmsdist/7351/19330/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: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 40
• DQMHistoTests: Total histograms compared: 3219394
• DQMHistoTests: Total failures: 11
• DQMHistoTests: Total nulls: 1
• DQMHistoTests: Total successes: 3219360
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.004 KiB( 39 files compared)
• DQMHistoSizes: changed ( 312.0 ): 0.004 KiB MessageLogger/Warnings
• Checked 169 log files, 37 edm output root files, 40 DQM output files
• TriggerResults: no differences found

[smuzaffar]

+externals

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next IB/CMSSW_12_1_X/master IBs (tests are also fine). 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)