iommu/omap: fix checkpatch warnings in omap iommu code

This patch fixes the checkpatch warnings in omap iommu
code, most of them are related to broken strings.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
diff --git a/drivers/iommu/omap-iopgtable.h b/drivers/iommu/omap-iopgtable.h
index cd4ae9e..f4003d5 100644
--- a/drivers/iommu/omap-iopgtable.h
+++ b/drivers/iommu/omap-iopgtable.h
@@ -95,4 +95,4 @@
 #define iopte_offset(iopgd, da)	(iopgd_page_vaddr(iopgd) + iopte_index(da))
 
 #define to_iommu(dev)							\
-	(struct omap_iommu *)platform_get_drvdata(to_platform_device(dev))
+	((struct omap_iommu *)platform_get_drvdata(to_platform_device(dev)))