[SCSI] fcoe: remove unused ptype field in fcoe_rcv_info

There is no need to cache the ptype in fcoe_rcv_info struct as it is never
used anywhere.

Signed-off-by: Yi Zou <yi.zou@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>