net: deflake TestAcceptTimeout again
net: deflake TestAcceptTimeout again

This is a followup to CL 33257.

It looks like active close operation at passive open side sometimes
takes a bit long time on Darwin.

Fixes #17948.

Change-Id: Ida17639c4e66a43e1be1f74fd0ef3baddde25092
Reviewed-on: https://go-review.googlesource.com/33258
Run-TryBot: Mikio Hara <e2f4d2eec1d9a1f781345cdd7260d7d52e6468ae@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

christopher-henderson/Go,cloudflare/go,codestation/go,golang/go,derekmarcotte/go,codestation/go,ImJasonH/go,nawawi/go,vsekhar/elastic-go,polyverse-security/go,goodlang/good,akutz/go,vsekhar/elastic-go,codestation/go,Cofyc/go,goodlang/good,josharian/go,josharian/go,Cofyc/go,golang/go,suncycheng/go,nawawi/go,vsekhar/elastic-go,codestation/go,polyverse-security/go,Cofyc/go,suncycheng/go,nawawi/go,Cofyc/go,josharian/go,josharian/go,goodlang/good,polyverse-security/go,akutz/go,vsekhar/elastic-go,suncycheng/go,nawawi/go,golang/go,golang/go,suncycheng/go,akutz/go,CAFxX/go,goodlang/good,linux-on-ibm-z/go,golang/go,suncycheng/go,ImJasonH/go,josharian/go,akutz/go,ImJasonH/go,josharian/go,derekmarcotte/go,suncycheng/go,linux-on-ibm-z/go,ImJasonH/go,golang/go,derekmarcotte/go,linux-on-ibm-z/go,vsekhar/elastic-go,linux-on-ibm-z/go,linux-on-ibm-z/go,suncycheng/go,cloudflare/go,Cofyc/go,Cofyc/go,CAFxX/go,Cofyc/go,CAFxX/go,linux-on-ibm-z/go,codestation/go,cloudflare/go,vsekhar/elastic-go,CAFxX/go,suncycheng/go,josharian/go,polyverse-security/go,ImJasonH/go,Cofyc/go,polyverse-security/go,akutz/go,nawawi/go,polyverse-security/go,goodlang/good,derekmarcotte/go,codestation/go,derekmarcotte/go,akutz/go,cloudflare/go,nawawi/go,linux-on-ibm-z/go,polyverse-security/go,CAFxX/go,goodlang/good,golang/go,nawawi/go,nawawi/go,ImJasonH/go,ImJasonH/go,ImJasonH/go,cloudflare/go,CAFxX/go,akutz/go,cloudflare/go,derekmarcotte/go,josharian/go,goodlang/good,codestation/go,codestation/go,akutz/go,derekmarcotte/go,vsekhar/elastic-go,derekmarcotte/go,cloudflare/go,cloudflare/go,polyverse-security/go,golang/go,linux-on-ibm-z/go,goodlang/good,CAFxX/go,CAFxX/go,vsekhar/elastic-go