cmd/link: write output in temp dir in TestUnlinkableObj
For unlinkable object the link will fail, but it opens the output
file in writable mode first then delete it on failure. This fails
if the current directory is not writable. Write to the temporary
directory instead.
Change-Id: Iefd73b5cc8efdc0f11b12edc0920169a8ad3f37c
Reviewed-on: https://go-review.googlesource.com/c/go/+/394755
Trust: Cherry Mui <cherryyz@google.com>
Run-TryBot: Cherry Mui <cherryyz@google.com> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>