elc_fileselector.c: check null path before fileselector populate.

If no path was selected we don't need to populate fileselector.
This fixes https://phab.enlightenment.org/T132.
Thanks uartie for the report.

legacy/elementary/src/lib/elc_fileselector.c

@@ -417,6 +417,7 @@ _populate(Evas_Object *obj,
           Elm_Object_Item *parent_it)
 {
    ELM_FILESELECTOR_DATA_GET(obj, sd);
+   if (!path) return;
 
 #ifdef HAVE_EIO
    Listing_Request *lreq;