testing: wrap long comment line
testing: wrap long comment line

Requested in CL 31324 review.

Change-Id: Ic81410e07cce07c6f3727bc46d86b6c54c15eca0
Reviewed-on: https://go-review.googlesource.com/31410
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

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