lxc_controller: Initialize ctrl->handshakeFd properly

lxc_controller: Initialize ctrl->handshakeFd properly

The lxc_controller has a structure that's keeping its internal
state, including so called handshakeFd which is the write end of
a pipe that's used to signal to the LXC driver that the container
is set up and ready to run. However, the struct member is not
initialized to -1, so if anything fails before it is set then the
virLXCControllerFree() function tries to close FD 0 (stdin).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>