Remove null bytes within a string

Null bytes have been observed within strings, remove them to
avoid the binary data in the output.

Change-Id: I651038c45ec346e66b4026c28c72499af8f378df

pyghmi/ipmi/fru.py

@@ -229,6 +229,7 @@ class FRU(object):
             # Additionally 0xfe has been observed, which should be a thorn, but
             # again assuming termination of string is more likely than thorn.
             retinfo = retinfo.rstrip(b'\xfe\xff\x10\x03\x00 ')
+            retinfo = retinfo.replace(b'\x00', b'')
             if lang in (0, 25):
                 try:
                     retinfo = retinfo.decode('iso-8859-1')