Fix use-after-free in DynamicTruncation::preliminaryFit (backport of 75X #9282 )

[slava77]

From 75X #9282 message

On the first iteration we used end() of STL container. end() returns
a pointer after the last element in container. In this case, we were
starting iteration from the last removed TrackingRecHit.

Signed-off-by: David Abdurachmanov David.Abdurachmanov@cern.ch

Somewhat anecdotal addendum:
I stumbled across this one while following up on a crash reported in
https://hypernews.cern.ch/HyperNews/CMS/get/tier0-Ops/1010/1/1/1/1/1/1/1/1/1/1/1/1/1/2/1/1/1/1/1/1/1/1/1/1/1/1/1/2/2/1/1/1/1/1.html
The FSQDiJetAve config had a crash in this part of DYT code when running with random memory allocation pattern

 export MALLOC_CHECK_=3 
 export MALLOC_PERTURB_=$(($RANDOM % 255 + 1))
cmsRunGlibC PSet.py

the crash on this event, however is not on the same event ("6578th record") nor in the same module as the one in the tier0-Ops.

[slava77]

+1

for #10027 43582b4

• the same code was integrated and tested in 75X (as implemented in Fix use-after-free in DynamicTruncation::preliminaryFit #9282 af475f9 )
• the crash that triggered retrieval of this PR from 75X to 74X is gone in a tested event.

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_4_X IBs once checked with relvals in the development release cycle of CMSSW or unless it breaks tests. This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @smuzaffar

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_4_X IBs once checked with relvals in the development release cycle of CMSSW or unless it breaks tests. This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @smuzaffar