drm/radeon: use locked rmmap to remove sarea mapping.

this exports the locked version of the symbol as struct_mutex locks it all.

Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 7fb690b..72c667f 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -440,6 +440,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL(drm_rmmap_locked);
 
 int drm_rmmap(struct drm_device *dev, drm_local_map_t *map)
 {
diff --git a/drivers/gpu/drm/radeon/radeon_cp.c b/drivers/gpu/drm/radeon/radeon_cp.c
index 4f5d1e9..63212d7 100644
--- a/drivers/gpu/drm/radeon/radeon_cp.c
+++ b/drivers/gpu/drm/radeon/radeon_cp.c
@@ -1804,7 +1804,7 @@
 
 	master_priv->sarea_priv = NULL;
 	if (master_priv->sarea)
-		drm_rmmap(dev, master_priv->sarea);
+		drm_rmmap_locked(dev, master_priv->sarea);
 
 	drm_free(master_priv, sizeof(*master_priv), DRM_MEM_DRIVER);