scsi: lpfc: Fix fcp_rsp_len checking on lun reset

Issuing a LUN reset was resulting in a command failure which then escalated
to a host reset.

The FCP-4 spec allows fcp_rsp_len field to specify the number of valid
bytes of FCP_RSP_INFO, and the value could be 4 or 8.  The driver is
allowing only a value of 8, thus it failed the command.

Revise the driver to allow 4 or 8.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>