Remove unnecessary Dup, Fcntl calls
Remove unnecessary Dup, Fcntl calls

We now rely on Go to "adopt" the file descriptors via `net.FileListner`
and `net.FilePacketConn`. Go sets flags like `O_CLOEXEC` and takes care
of blocking modes.

Signed-off-by: David Scott <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@recoil.org>

djs55/vpnkit,djs55/vpnkit,djs55/vpnkit