tst_run_cmd: add an option to pass the program exit code

Added an option to pass the program exit code to the caller.
This may be needed if we want to run a program with tst_run_cmd(),
but handle failures manually (i.e. not call cleanup).

Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Acked-by: Cyril Hrubis <chrubis@suse.cz>
5 files changed