drm: DRM: fix memset size error

The size passing to memset is wrong.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/char/drm/drm_ioctl.c

@@ -272,7 +272,7 @@ int drm_getstats(struct drm_device *dev, void *data,
 	struct drm_stats *stats = data;
 	int i;
 
-	memset(stats, 0, sizeof(stats));
+	memset(stats, 0, sizeof(*stats));
 
 	mutex_lock(&dev->struct_mutex);