fix for number of secondary vertex tracks in case IVF vertices are used

[pvmulder]

This fix does not affect the any b-tagger in the RECO sequence, it only affects the performance when IVF is used and even in that case the performance is very similar, as can be seen in the figure.

[slava77]

@cmsbuild please get this on a regular list of PRs with labels, milestones and such

[cmsbuild]

A new Pull Request was created by @pvmulder (Petra Van Mulders) for CMSSW_7_0_X.

fix for number of secondary vertex tracks in case IVF vertices are used

It involves the following packages:

RecoBTag/SecondaryVertex

@cmsbuild, @nclopezo, @StoyanStoynev, @slava77 can you please review it and eventually sign? Thanks.
@ferencek this is something you requested to watch as well.
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@nclopezo, @ktf you are the release manager for this.
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[cmsbuild]

+1
Tested at: 84bc6b8
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-5085/261/summary.html

[slava77]

+1

for #5085 84bc6b8
(the code doesn't run in standard seqs)
changes are consistent with what's done in #5160

(tested in CMSSW_7_0_8 test area sign709b)

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_0_X IBs unless changes (tests are also fine). @nclopezo, @ktf can you please take care of it?