Logging message when need to truncate name/description fields

Author: cmart

cinderback.py

@@ -288,8 +288,10 @@ def __init__(self, data):
             self.name = data.name
             self.description = data.description
             if len(self.__repr__()) > 255:
+                _LI('Backup description too long, truncating description field')
                 self.description = ''
                 if len(self.__repr__()) > 255:
+                    _LI('Backup description still too long, truncating name field')
                     self.name = ''
 
         # We don't know how to treat additional types