Make ALSA devices without description appear in Qt4 config.

If an /etc/asound.conf or $HOME/.asoundrc creates devices, those do not have a
description (a null pointer is returned). Relatedly, redefining the "default"
device results in it being listed without a description, thus disabling the
code that adds "default" WITH a description.
Possibly fixes other problems where ALSA devices with a NULL
description are disregarded. In Qt4 config, the NULL check is in
StringListConfigControl::finish().
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/audio_output/alsa.c

@@ -738,9 +738,10 @@ static int EnumDevices(vlc_object_t *obj, char const *varname,
             continue;
 
         char *desc = snd_device_name_get_hint(hint, "DESC");
-        if (desc != NULL)
-            for (char *lf = strchr(desc, '\n'); lf; lf = strchr(lf, '\n'))
-                 *lf = ' ';
+        if (desc == NULL)
+            desc = xstrdup (name);
+        for (char *lf = strchr(desc, '\n'); lf; lf = strchr(lf, '\n'))
+            *lf = ' ';
         msg_Dbg (obj, "%s (%s)", (desc != NULL) ? desc : name, name);
 
         ids = xrealloc (ids, (n + 1) * sizeof (*ids));