util/abuild: Clean up the missing_arches check

This change adds the following improvements:
* Easier to read.
* Checks to see if .xcompile is complete.
* Checks the make return code. This will catch if .xcompile is missing.

BUG=b:112267918
TEST=Modified my .xcompile and ran abuild and verified that
missing_arches got set correctly. Also deleted .xcompile and verified
there was a failure.

Change-Id: I7604d431f398fc0c80a857a0c7c21e164004cc99
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34241
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

0 files changed, 0 insertions, 0 deletions