[SCSI] bfa: Fix to set correct return error codes and misc cleanup.

- Remove unnecessary if NULL check in function bfa_fcs_vport_free().
- Set correct return error codes in case of memory allocation failure
  in the BSG ELS/CT passthru command handler.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>