iscsi-initiator-utils: fix the iscsid path in iscsid.conf

iscsid is installed into ${sbindir}, which is /usr/sbin, not /sbin/,
so fix it in /etc/iscsi/iscsid.conf

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>