BarcodeServices: fix clang warnings

Fix clang warnings in BarcodeServices.

This merge request affects 1 package:

• Simulation/Barcode/BarcodeServices

This merge request affects 1 file:

• Simulation/Barcode/BarcodeServices/BarcodeServices/ValidationBarcodeSvc.h

Adding @jchapman as watcher

added Simulation main review-pending-level-1 labels

CI Result SUCCESS (hash ed1d8275)

	Athena	AthSimulation
externals
cmake
make
tests

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Athena: number of compilation errors 0, warnings 0
AthSimulation: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-EL9 9569] (remote access info)

Looks good, approving - L2

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

merged

mentioned in commit c3013cfa