virsh: Fix comment for net-undefine

net-undefine doesn't only undefine an inactive network,
but also an active network(persistent), it just cannot
undefine a transient network.
Signed-off-by: NLi Yang <liyang.fnst@cn.fujitsu.com>
Signed-off-by: NJán Tomko <jtomko@redhat.com>

tools/virsh-network.c

@@ -798,10 +798,10 @@ cmdNetworkStart(vshControl *ctl, const vshCmd *cmd)
  */
 static const vshCmdInfo info_network_undefine[] = {
     {.name = "help",
-     .data = N_("undefine an inactive network")
+     .data = N_("undefine a persistent network")
     },
     {.name = "desc",
-     .data = N_("Undefine the configuration for an inactive network.")
+     .data = N_("Undefine the configuration for a persistent network.")
     },
     {.name = NULL}
 };

tools/virsh.pod

@@ -2590,7 +2590,8 @@ Start a (previously defined) inactive network.
 
 =item B<net-undefine> I<network>
 
-Undefine the configuration for an inactive network.
+Undefine the configuration for a persistent network. If the network is active,
+make it transient.
 
 =item B<net-uuid> I<network-name>