There's no point in setting cmd.ExtraFiles if the fds array is an
empty slice. This won't do any harm but is essentially a no-op.
Signed-off-by: Mark Ryan <mark.d.ryan@intel.com>
This commit adds some package documentation to the qemu package,
including an overview of the package and an example of its use.
Signed-off-by: Mark Ryan <mark.d.ryan@intel.com>