net: update renamed test name in comment
net: update renamed test name in comment

TestSelfConnect from CL 5650071 was renamed TestTCPSelfConnect in CL 21447.

Change-Id: I0de110dbe1da77bfba540a1b51c139f3bedae67f
Reviewed-on: https://go-review.googlesource.com/c/go/+/213437
Reviewed-by: Tobias Klauser <0a68dd4915066ec5d3f81f75a828fee53dcc8822@gmail.com>

CAFxX/go,nawawi/go,akutz/go,nawawi/go,golang/go,CAFxX/go,nawawi/go,golang/go,CAFxX/go,akutz/go,cloudflare/go,nawawi/go,CAFxX/go,cloudflare/go,golang/go,nawawi/go,akutz/go,akutz/go,CAFxX/go,golang/go,akutz/go,akutz/go,golang/go,golang/go,CAFxX/go,CAFxX/go,cloudflare/go,cloudflare/go,nawawi/go,golang/go,nawawi/go,cloudflare/go,akutz/go,cloudflare/go,akutz/go,cloudflare/go,golang/go,CAFxX/go,nawawi/go,cloudflare/go