search: Do not error in location dialog when an XDG directory is `$HOME`

`path_from_tracker_dir()` shouldn't return `NULL` since the functions
calling it do not check for a `NULL` return value.

Reported in https://github.com/pop-os/gnome-control-center/issues/149

panels/search/cc-search-locations-dialog.c

@@ -238,21 +238,21 @@ path_from_tracker_dir (const gchar *value)
   const gchar *path;
 
   if (g_strcmp0 (value, "&DESKTOP") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_DESKTOP);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_DESKTOP);
   else if (g_strcmp0 (value, "&DOCUMENTS") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_DOCUMENTS);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_DOCUMENTS);
   else if (g_strcmp0 (value, "&DOWNLOAD") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_DOWNLOAD);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_DOWNLOAD);
   else if (g_strcmp0 (value, "&MUSIC") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_MUSIC);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_MUSIC);
   else if (g_strcmp0 (value, "&PICTURES") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_PICTURES);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_PICTURES);
   else if (g_strcmp0 (value, "&PUBLIC_SHARE") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_PUBLIC_SHARE);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_PUBLIC_SHARE);
   else if (g_strcmp0 (value, "&TEMPLATES") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_TEMPLATES);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_TEMPLATES);
   else if (g_strcmp0 (value, "&VIDEOS") == 0)
-    path = get_user_special_dir_if_not_home (G_USER_DIRECTORY_VIDEOS);
+    path = g_get_user_special_dir (G_USER_DIRECTORY_VIDEOS);
   else if (g_strcmp0 (value, "$HOME") == 0)
     path = g_get_home_dir ();
   else