iommu/amd: fix type bug in flush code

write_file_bool() modifies 32 bits of data, so "amd_iommu_unmap_flush"
needs to be 32 bits as well or we'll corrupt memory.  Fortunately it
looks like the data is aligned with a gap after the declaration so this
is harmless in production.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index dfe7d37..6256263 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -404,7 +404,7 @@
 		return;
 
 	de_fflush  = debugfs_create_bool("fullflush", 0444, stats_dir,
-					 (u32 *)&amd_iommu_unmap_flush);
+					 &amd_iommu_unmap_flush);
 
 	amd_iommu_stats_add(&compl_wait);
 	amd_iommu_stats_add(&cnt_map_single);