Sometimes the compiler doesn't like { 0, } as an initializer...

Sometimes the compiler doesn't like { 0, } as an initializer...

Because it really wants to be { {0, },} or something, and sometimes the
compiler, knowing full well what we're trying to do, likes to complain
about the rigor applied to our technique in doing it.

memset() the struct ifreq to 0 instead so I don't need to figure out its
internal structure just to zero it out.

Resolves #28

Signed-off-by: Peter Jones <pjones@redhat.com>