Problem: PVS Studio static analyser reports some issues

[pavel-pimenov]

Report:
http://www.fly-server.ru/pvs-studio/libzmq

[bluca]

Could you please give a bit more details of what this is and how to reproduce results?

[pavel-pimenov]

Reproduce result: install https://www.viva64.com/en/pvs-studio/

[bluca]

Feel free to triage them to separate false positives from real issue and send fixes.

[bluca]

Some fixes in: #2984