libnet: Fix the check of the argument lengths of the "ping" command

The current if-condition can never be true.

Buglink: https://bugs.launchpad.net/qemu/+bug/1840646
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
1 file changed