Needed for PATH variable to be passed into su. The
posix* tests were fixed, but they need further investigation
before they can be enabled.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Closes#6303