AthenaPoolCnvSvc: cppcheck fixes

• Use starts_with instead of find()==0.
• Use prefix ++ rather than postfix.

This merge request affects 1 package:

• Database/AthenaPOOL/AthenaPoolCnvSvc

Adding @ssnyder ,@mnowak as watchers

added Database master review-pending-level-1 labels

CI Result SUCCESS (hash 9400666e)

	Athena	AthSimulation	AnalysisBase	AthGeneration
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
AnalysisBase: number of compilation errors 0, warnings 0
AthGeneration: number of compilation errors 0, warnings 0
For experts only: Jenkins output [CI-MERGE-REQUEST-CC7 15823]

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

merged

mentioned in commit 901ff577

added sweep:ignore label