udp: Update reuse->hasconns under reuseportlock.
This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven. This ID is fixed in Linux Kernel version v5.10.152 by commit 43d5109296fab30b7467d7d399bb51f1bb27eff4, it was introduced in version v5.4 by commit acdcecc61285faed359f1a3568c32089cc3a8329. For more details please see the references link.