[SCSI] zfcp: Apply common naming conventions to zfcp_fc

Update the Fibre Channel related code to use the zfcp_fc prefix.

Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>