[SCSI] libfc, fcoe, bnx2fc: cleanup fcoe_dev_stats

The libfc is used by fcoe but fcoe agnostic,
and therefore should not have any fcoe references.

So renaming fcoe_dev_stats from libfc as its for fc_stats.
After that libfc is fcoe string free except some strings for
Open-FCoE.org.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Acked-by : Robert Love <robert.w.love@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Acked-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>