qla1280: Don't allocate 512kb of host tags

The qla1280 driver sets the scsi_host_template's can_queue field to 0xfffff
which results in an allocation failure when allocating the block layer tags
for the driver's queues. This was introduced with the change for host wide
tags in commit 64d513ac - "scsi: use host wide tags by default".

Reduce can_queue to MAX_OUTSTANDING_COMMANDS (512) to solve the allocation
error.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 64d513ac - "scsi: use host wide tags by default"
Cc: stable@vger.kernel.org # v4.4
Cc: Laura Abbott <labbott@redhat.com>
Cc: Michael Reed <mdr@sgi.com>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Lee Duncan <lduncan@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <jejb@linux.vnet.ibm.com>