MuonTrackFinderTools+MuonCalibTools+MuonPrepRawDataProviderTools: Fix clang warnings.

References cannot be null, so it makes no sense to test their address for null.

This merge request affects 3 packages:

• MuonSpectrometer/MuonCalib/MuonCalibTools
• MuonSpectrometer/MuonCnv/MuonPrepRawDataProviderTools
• MuonSpectrometer/MuonReconstruction/MuonTrackMakers/MuonTrackMakerTools/MuonTrackFinderTools

Adding @rosati ,@wleight ,@nkoehler as watchers

added MuonSpectrometer master review-pending-level-1 labels

CI Result SUCCESS (hash 85084eba)

	Athena	AthSimulation
externals
cmake
make
required tests
optional tests

Full details available on this CI monitor view
Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 4797]

added review-approved label and removed review-pending-level-1 label

merged

mentioned in commit b26558f5

added sweep:ignore label