Retire private id executables

Retire private id executables

The main script is setting PATH to use id executable from rather
strange directory.  That allowed checks to run without root
privilege.  This change will make detection whether test run is
been requested more universal, and to work without super setting
id command.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
RWMJ:
  - Use -ne instead of != to compare integers.

(cherry picked from commit 8aa72773cebbc742d9378fed6b6ac13cb57b0eb3)