scsi: be2iscsi: Update iface handle before any set param

Move mgmt_get_all_if_id before any set param operation.
Rename mgmt_get_all_if_id to beiscsi_if_get_handle.

Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>