scsi: bnx2fc: Make rport_terminate_io callback a NOOP.

Do not call the stock libfc terminate rport i/o handler so we won't reset
the libfc exchange manager and kill any outstanding discovery requests.

Signed-off-by: Chad Dupuis <chad.dupuis@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>