Merge branch 'wireguard-fixes-for-6-17-rc6'

Jason A. Donenfeld says:

====================
wireguard fixes for 6.17-rc6

Please find three small fixes to wireguard:

1) A general simplification to the way wireguard chooses the next
   available cpu, by making use of cpumask_nth(), and covering an edge
   case.

2) A cleanup to the selftests kconfig.

3) A fix to the selftests kconfig so that it actually runs again.
====================

Link: https://patch.msgid.link/20250910013644.4153708-1-Jason@zx2c4.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>