[SCSI] scsi_dh: Update EMC handler

This patch converts the EMC device handler to use a proper
state machine. We now also parse the extended INQUIRY
information to determine if long trespass commands are
supported. And we're now using the long trespass command
correctly. And finally there's now an check at init time
to refuse to attach to devices not supporting EMC-specific
VPD pages.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

include/scsi/scsi_dh.h

@@ -32,6 +32,7 @@ enum {
 	 */
 	SCSI_DH_DEV_FAILED,	/* generic device error */
 	SCSI_DH_DEV_TEMP_BUSY,
+	SCSI_DH_DEV_UNSUPP,	/* device handler not supported */
 	SCSI_DH_DEVICE_MAX,	/* max device blkerr definition */
 
 	/*