shell: Break up a few long lines
diff --git a/src/shell.c b/src/shell.c
index feb388f..76ffed7 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1932,6 +1932,7 @@
 	struct weston_compositor *compositor = switcher->compositor;
 	struct weston_surface *surface;
 	struct weston_surface *first = NULL, *prev = NULL, *next = NULL;
+	struct shell_surface *shsurf;
 
 	wl_list_for_each(surface, &compositor->surface_list, link) {
 		switch (get_shell_surface_type(surface)) {
@@ -1971,8 +1972,9 @@
 	switcher->current = next;
 	next->alpha = 255;
 
-	if (get_shell_surface_type(switcher->current) == SHELL_SURFACE_FULLSCREEN)
-		get_shell_surface(switcher->current)->fullscreen.black_surface->alpha = 255;
+	shsurf = get_shell_surface(switcher->current);
+	if (shsurf && shsurf->type ==SHELL_SURFACE_FULLSCREEN)
+		shsurf->fullscreen.black_surface->alpha = 255;
 }
 
 static void