lpfc: Fix vport deletion failure.

If a vport was deleted while in the middle of discovery, we weren't
clearing the nport discovery flag. Correct by clearing the flag and
cancelling our discovery timeout timer.

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>