The script where behaving badly when the session directory does not
exist and also lacking a dependency to 'sudo'. Instead of adding a
dependency on 'sudo' we use 'su' as done in xserver-common.
(From OE-Core rev: 84b58ed421fd14796ddcbc4cc7fc13a5a098d6cc)
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>