VxVertex and VKalVrt reduce log spam and nulling

Reduce the log print out and the nulling of memory that is immediately deallocated (this code is mature and doesn't need training wheels).

This merge request affects 2 packages:

• Tracking/TrkEvent/VxVertex
• Tracking/TrkVertexFitter/TrkVKalVrtFitter

Affected files list will not be printed in this case

Adding @amorley as watcher

added Tracking master review-pending-level-1 labels

CI Result SUCCESS (hash 439e765c)

	Athena	AthSimulation	AthGeneration	AnalysisBase	AthAnalysis	DetCommon
externals
cmake
make
tests

Full details available on this CI monitor view. Check the JIRA CI status board for known problems
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
AthAnalysis: number of compilation errors 0, warnings 0
DetCommon: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 58650]

Approved
Albert (L1)

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

merged

mentioned in commit 757c0dc0

added sweep:ignore label

Hi @abarton - I think this caused ATLASRECTS-7276

mentioned in merge request !56650 (merged)