wgengine/magicsock: fix recently introduced data race

Browse Source

From 5c42990c2f, not yet released in a stable build.
Caught by existing tests.

Fixes #5685

Change-Id: Ia76bb328809d9644e8b96910767facf627830600
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

...

This commit is contained in:

500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f