mm, drm/udl: fixup vma flags on mmap

There should be VM_MIXEDMAP, not VM_PFNMAP, because udl_gem_fault() inserts
pages via vm_insert_page(). Other drm/gem drivers already do this.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/udl/udl_gem.c b/drivers/gpu/drm/udl/udl_gem.c
index 852642d..92f19ef 100644
--- a/drivers/gpu/drm/udl/udl_gem.c
+++ b/drivers/gpu/drm/udl/udl_gem.c
@@ -71,6 +71,20 @@
 	return drm_gem_handle_delete(file, handle);
 }
 
+int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int ret;
+
+	ret = drm_gem_mmap(filp, vma);
+	if (ret)
+		return ret;
+
+	vma->vm_flags &= ~VM_PFNMAP;
+	vma->vm_flags |= VM_MIXEDMAP;
+
+	return ret;
+}
+
 int udl_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct udl_gem_object *obj = to_udl_bo(vma->vm_private_data);