TrackVertexAssociationTool: Fix clang warnings.

If a class has final destructor, the whole class should be final (not possible to derive from it).

Also avoid using non-portable attribute.

This merge request affects 1 package:

• InnerDetector/InDetRecTools/TrackVertexAssociationTool

Adding @goetz ,@sroe ,@amorley ,@dshope as watchers

added InnerDetector master review-pending-level-1 labels

CI Result SUCCESS (hash 8934f432)

	Athena	AthSimulation	AthGeneration	AnalysisBase
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
AthGeneration: number of compilation errors 0, warnings 0
AnalysisBase: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 21496]

merged

mentioned in commit 050e0ede

added sweep:ignore label