libchromeos: Use sh instead of bash in process_test.

Don't rely on bash for sh functionality. This allows the unittests to
run on system that don't have bash.

BUG=None
TEST=`FEATURES=test emerge-gizmo libchromeos --nodeps` works.

CQ-DEPEND=CL:287404

Change-Id: Icf3ae17a9a4f0553e5c623927d25d60303b88306
Reviewed-on: https://chromium-review.googlesource.com/287405
Trybot-Ready: Bertrand Simonnet <bsimonnet@chromium.org>
Tested-by: Bertrand Simonnet <bsimonnet@chromium.org>
Reviewed-by: Christopher Wiley <wiley@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Commit-Queue: Bertrand Simonnet <bsimonnet@chromium.org>
1 file changed