pygrub: if default entry is "saved" then use first entry.

pygrub doesn't support the "savedefault" command and will error out if
menu.lst uses the "default saved" directive. We might as well start on
the first entry in this case instead of failing.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>

tools/pygrub/src/GrubConf.py

@@ -258,7 +258,7 @@ class GrubConfigFile(object):
         return self._default
     def _set_default(self, val):
         if val == "saved":
-            self._default = -1
+            self._default = 0
         else:
             self._default = int(val)