[SCSI] libfcoe: add debug message for FCF destination MAC

When multiple FCFs to the same fabric exist, the debug messages
all look alike.   Change the message to include the MAC address.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>