Cleanup #4004

[ktf]

As discussed, this corrects the behavior of #4004 getting back the old behavior and still keeping clang happy.

[cmsbuild]

A new Pull Request was created by @ktf (Giulio Eulisse) for CMSSW_7_1_X.

Cleanup #4004

It involves the following packages:

MuonAnalysis/MomentumScaleCalibration

@nclopezo, @vadler, @cmsbuild, @Degano, @monttj can you please review it and eventually sign? Thanks.
@mmusich, @frmeier, @argiro 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.
You can reject by replying to this message having '-1' in the first line of your reply.
@nclopezo, @ktf you are the release manager for this.
You can merge this pull request by typing 'merge' in the first line of your comment.

[ktf]

Bypassing signatures since this is agreed to be the correct behavior.
@StoyanStoynev