[SCSI] libfc: move rport_lookup into fc_rport.c

Move the libfc remote port lookup function into fc_rport.c.
This seems like the best place for it.

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>