lib/subprocess: style updates

Just resolving some style comments left on CL:1955805. The CL merged
by CQ before I noticed the comments.

BUG=none
BRANCH=none
TEST=compiles

Change-Id: I286343e3ee2ecb4cb6092ca99fa46c4a80442e03
Signed-off-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/1957760
Tested-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
3 files changed