Fix warning section formatting and link reference

Removed unnecessary line break and updated link reference in the warning section.

Author: guywi-ms

articles/sentinel/multiple-tenants-service-providers.md

@@ -15,8 +15,7 @@ ms.date: 11/11/2024
 If you're a managed security service provider (MSSP) and you're using [Azure Lighthouse](/azure/lighthouse/overview) to offer security operations center (SOC) services to your customers, you can manage your customers' Microsoft Sentinel resources directly from your own Azure tenant, without having to connect to the customer's tenant. 
 
 > [!IMPORTANT]
-
-> After **March 31, 2027**, Microsoft Sentinel will no longer be supported in the Azure portal and will be available only in the Microsoft Defender portal. All customers using Microsoft Sentinel in the Azure portal will be [redirected to the Defender portal and will use Microsoft Sentinel in the Defender portal only](../overview.md#microsoft-sentinel-in-the-azure-portal-retirement-timeline).
+> After **March 31, 2027**, Microsoft Sentinel will no longer be supported in the Azure portal and will be available only in the Microsoft Defender portal. All customers using Microsoft Sentinel in the Azure portal will be [redirected to the Defender portal and will use Microsoft Sentinel in the Defender portal only](overview.md#microsoft-sentinel-in-the-azure-portal-retirement-timeline).
 >
 > If you're still using Microsoft Sentinel in the Azure portal, we recommend that you start planning your move to the Defender portal to ensure a smooth experience and to take full advantage of unified security operations and multitenant management capabilities offered by the Defender portal. For guidance and best practices, see the [Microsoft Defender portal implementation guide for MSSPs](/unified-secops/playbook-managed-security).