Remove cerr left in inadvertently

[wmtan]

In a recent improvement, PR #9091, I inadvertently left in a std::cerr statement I used to debug it.
This trivial PR simply removes the statement, which was causing IB logs to fill up.

[cmsbuild]

A new Pull Request was created by @wmtan for CMSSW_7_5_X.

Remove cerr left in inadvertently

It involves the following packages:

IOPool/Input

@cmsbuild, @Dr15Jones, @nclopezo can you please review it and eventually sign? Thanks.
@wddgit this is something you requested to watch as well.
You can sign-off by replying to this message having '+1' in the first line of your reply.
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@nclopezo you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[Dr15Jones]

please test

[Dr15Jones]

+1

[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_5_X IBs unless changes or unless it breaks tests. This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @nclopezo, @smuzaffar

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs unless changes or unless it breaks tests. This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @nclopezo, @smuzaffar