iommu/vt-d: Use memunmap to free memremap

BugLink: https://bugs.launchpad.net/bugs/1811077

[ Upstream commit 829383e1 ]

memunmap() should be used to free the return of memremap(), not
iounmap().

Fixes: dfddb969 ('iommu/vt-d: Switch from ioremap_cache to memremap')
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/iommu/intel-iommu.c

@@ -2977,7 +2977,7 @@ static int copy_context_table(struct intel_iommu *iommu,
 			}
 
 			if (old_ce)
-				iounmap(old_ce);
+				memunmap(old_ce);
 
 			ret = 0;
 			if (devfn < 0x80)