Remove virtual where it is not required.
Remove virtual where it is not required.

Adding override instead allows the compiler to generate and error when:

- The base class implementation function signature changes.
- The user has not created the override with the correct signature.

Change-Id: I8eaa87ba6837471840d9cbdeee16bcaa0966188a
Reviewed-by: Scott Parlane <85029adc3fa41ef14594a57826619713bfe95f25@alliedtelesis.co.nz>
Signed-off-by: Matt Bennett <e3d8681cec70d3da741935b3385821001b249adc@alliedtelesis.co.nz>

ATL-NZ/buildsyspp,alliedtelesis/buildsyspp