common.sh: add ps call in dump_trace() to show all commands

This adds a "ps" call in dump_trace() to expose hidden commands and
ease trouble-shooting.

Compared to earlier and well-tested attempt
https://chromium-review.googlesource.com/#/q/I7978bcf03bd279e3bcce17a239ae0301868d8601
... this has two drawbacks: 1. it does not wrap long lines; 2. it
shows two spurious processes: the subshell + the ps call.

However it has one major advantage: it's only one line long instead of fifty.

BUG=None
TEST=./build_image make_it_fail
TEST=Insert "die fake_failure" at the top of update_bootloaders.sh
./build_image base

Change-Id: Iad269ab19d923a8e1efb1222e309bbf88707d991
Signed-off-by: Marc Herbert <marc.herbert@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/273685
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed