According to Anthony Cheung all HP XP arrays with "OPEN-" 
types support REPORT_LUN. So there is no reason why we
shouldn't use it.
Signed-off-by: NAnthony Cheung <anthony.cheung@hp.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>