cmd/dist: test: use existing globals rather than environment variables
cmd/dist: test: use existing globals rather than environment variables

Change-Id: Ief6bad2d15461d455e7230eadd9b42b27d04ec8b
Reviewed-on: https://go-review.googlesource.com/64630
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

josharian/go,akutz/go,polyverse-security/go,golang/go,nawawi/go,akutz/go,josharian/go,nawawi/go,golang/go,codestation/go,josharian/go,akutz/go,golang/go,cloudflare/go,polyverse-security/go,polyverse-security/go,akutz/go,akutz/go,nawawi/go,CAFxX/go,golang/go,golang/go,cloudflare/go,josharian/go,CAFxX/go,Cofyc/go,josharian/go,Cofyc/go,polyverse-security/go,polyverse-security/go,golang/go,CAFxX/go,Cofyc/go,Cofyc/go,Cofyc/go,cloudflare/go,akutz/go,Cofyc/go,CAFxX/go,polyverse-security/go,CAFxX/go,polyverse-security/go,CAFxX/go,cloudflare/go,josharian/go,christopher-henderson/Go,nawawi/go,Cofyc/go,josharian/go,nawawi/go,cloudflare/go,CAFxX/go,codestation/go,josharian/go,nawawi/go,polyverse-security/go,akutz/go,cloudflare/go,CAFxX/go,codestation/go,nawawi/go,codestation/go,nawawi/go,Cofyc/go,codestation/go,cloudflare/go,codestation/go,golang/go,codestation/go,codestation/go,golang/go,akutz/go,cloudflare/go