[SCSI] bnx2fc: code cleanup in bnx2fc_offload_session

- Free session resources before rport logoff
- Do not free session resources in bnx2fc_alloc_session_resc() as it is handled
  in caller's error handling path.
- Do not call bnx2fc_free_session_resc() if bnx2fc_init_tgt() fails as cq_lock
  is not yet initialized.

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>