debug/pe: improve testpoint error message
debug/pe: improve testpoint error message

A DWARF testpoint was calling t.Fatal() but should have been calling
t.Fatalf(); switch it to the correct method.

Change-Id: I996a1041adea4299cda85c147a35b513a219b970
Reviewed-on: https://go-review.googlesource.com/c/go/+/228790
Run-TryBot: Than McIntosh <4b2922593166fc595a9b1a408f34f5d3817fe9d2@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Jeremy Faller <b3f594e10a9edcf5413cf1190121d45078c62290@golang.org>
Reviewed-by: Cherry Zhang <d62e63aa42ce272d7b6a5055d97e942b33a34679@google.com>

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