lpfc: Check for active portpeerbeacon.

LCB requests to set Beacon would fail if the beacon was already enabled
internally as the mailbox command used to query the state failes with
an already-set status.

Correct by enhancing the check so we don't fail if if the already set
status comes back.

Signed-off-by: Dick Kennedy <dick.kennedy@avagotech.com>
Signed-off-by: James Smart <james.smart@avagotech.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>