[SCSI] fcoe: use ETH_P_FIP for skb->protocol of FIP frames

FIP frames should leave the fcoe layer with skb->protocol set to
ETH_P_FIP, not ETH_P_802_3.

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>