Unnecessary; covered by https://golang.org/cl/141690043

Verified by jonathan@titanous.com on golang-dev.

««« original CL description
cmd/ld: close outfile before cleanup

This prevents the temporary directory from being leaked when
the linker is run on a FUSE filesystem.

Fixes #8684.

LGTM=bradfitz
R=golang-codereviews, rsc, bradfitz
CC=golang-codereviews
https://golang.org/cl/141840043

»»»

LGTM=jonathan, iant
R=iant, jonathan
CC=golang-codereviews
https://golang.org/cl/150250045