OVSDriver: workaround valgrind not understanding ethtool
OVSDriver: workaround valgrind not understanding ethtool

Valgrind complains that the fields populated by the ethtool ioctl are
uninitialized, when actually the kernel wrote to them. Work around this by
initializing the result before the ioctl.

vezril/ivs,harshsin/ivs,harshsin/ivs,floodlight/ivs,floodlight/ivs,vezril/ivs,harshsin/ivs,vezril/ivs,floodlight/ivs,harshsin/ivs