tooltip: force place() if tooltip is not visible

Commit 6c5d0ca9 introduced a side effect. If tooltip text isn't changed
place() function is not called. To prevent multiple place() set_geometry
calls that function when tooltip is not visible (before it appears to the
user).

Signed-off-by: Sébastien Gross <seb•ɱɩɲʋʃ•awesome•ɑƬ•chezwam•ɖɵʈ•org>
Signed-off-by: Julien Danjou <julien@danjou.info>

lib/awful/tooltip.lua.in

@@ -82,6 +82,9 @@ local function set_geometry(self)
         self.wibox:geometry(n_s)
         place(self)
     end
+    if not self.wibox.visible then
+       place(self)
+    end
 end
 
 -- Show a tooltip.