Provide better error handling for XCC/IMM

The UEFI configuration can fail out.

Change-Id: I0e6fc5630f6bb9df02512b8d3a3818e5f1d283a0

pyghmi/ipmi/oem/lenovo/config.py

@@ -268,7 +268,8 @@ class LenovoFirmwareConfig(object):
             if len(data) != 0:
                 break
             self.connection.ipmi_session.pause(2)
-
+        if not data:
+            raise Exception("BMC failed to return configuration information")
         xml = etree.fromstring(data)
         sortid = 0
         for config in xml.iter("config"):

pyghmi/ipmi/oem/lenovo/imm.py

@@ -171,7 +171,10 @@ class IMMClient(object):
     def get_system_configuration(self, hideadvanced=True):
         if not self.fwc:
             self.fwc = config.LenovoFirmwareConfig(self.ipmicmd)
-        self.fwo = self.fwc.get_fw_options()
+        try:
+            self.fwo = self.fwc.get_fw_options()
+        except Exception:
+            raise Exception(self.bmcname + ' failed to retrieve UEFI configuration')
         self.fwovintage = util._monotonic_time()
         retcfg = {}
         for opt in self.fwo: