ncr5380: Reduce max_lun limit

The driver has a limit of eight LUs because of the byte-sized bitfield
that is used for busy flags. That means the maximum LUN is 7. The default
is 8.
Signed-off-by: NFinn Thain <fthain@telegraphics.com.au>
Tested-by: NMichael Schmitz <schmitzmic@gmail.com>
Tested-by: NOndrej Zary <linux@rainbow-software.org>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/NCR5380.c

@@ -488,6 +488,8 @@ static int NCR5380_init(struct Scsi_Host *instance, int flags)
 	int i;
 	unsigned long deadline;
 
+	instance->max_lun = 7;
+
 	hostdata->host = instance;
 	hostdata->id_mask = 1 << instance->this_id;
 	hostdata->id_higher_mask = 0;