cmd/go: update test script for reformatted error message (fix long builds)
cmd/go: update test script for reformatted error message (fix long builds)

TBR=iant

Change-Id: Ic72af52e5ff8d28f8102c07b03e4930df61445ca
Reviewed-on: https://go-review.googlesource.com/c/go/+/358115
Trust: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>
Trust: Cuong Manh Le <54b4457f1dff6823379654eb5867596497ba782f@gmail.com>
Run-TryBot: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Cuong Manh Le <54b4457f1dff6823379654eb5867596497ba782f@gmail.com>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

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