x64, x2apic/intr-remap: Fix the need for RMRR in the DMA-remapping detection

Presence of RMRR structures is not compulsory for enabling DMA-remapping.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NYong Y Wang <yong.y.wang@intel.com>
Cc: Yong Y Wang <yong.y.wang@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: NIngo Molnar <mingo@elte.hu>

drivers/pci/dmar.c

@@ -419,10 +419,8 @@ int __init dmar_table_init(void)
 	}
 
 #ifdef CONFIG_DMAR
-	if (list_empty(&dmar_rmrr_units)) {
+	if (list_empty(&dmar_rmrr_units))
 		printk(KERN_INFO PREFIX "No RMRR found\n");
-		return -ENODEV;
-	}
 #endif
 
 	return 0;