Coverty scan found this:
> CID 298295 (#1 of 1): Operands don't affect result (CONSTANT_EXPRESSION_RESULT) result_independent_of_operands:
> (ipv6_hdr_get_fl(ipv6_hdr) & 255) >> 8 is 0 regardless of the values of its operands.
Looking at the code, this appears to be a copy & paste error from the previous line.