PCI iommu: iommu=pt is a valid early param

This avoids a "Malformed early option 'iommu'" on boot when trying
to use pass-through mode.

Signed-off-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 1a041bc..ae13e34 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -212,10 +212,8 @@
 		if (!strncmp(p, "soft", 4))
 			swiotlb = 1;
 #endif
-		if (!strncmp(p, "pt", 2)) {
+		if (!strncmp(p, "pt", 2))
 			iommu_pass_through = 1;
-			return 1;
-		}
 
 		gart_parse_options(p);