qemu-options: update to show preferred boolean syntax for -netdev

The preferred syntax is to use "foo=on|off", rather than a bare
"foo" or "nofoo".

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210216191027.595031-5-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

qemu-options.hx

@@ -2406,8 +2406,8 @@ DEFHEADING(Network options:)
 
 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
 #ifdef CONFIG_SLIRP
-    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
-    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
+    "-netdev user,id=str[,ipv4=on|off][,net=addr[/mask]][,host=addr]\n"
+    "         [,ipv6=on|off][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
     "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
     "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,domainname=domain]\n"
     "         [,tftp=dir][,tftp-server-name=name][,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
@@ -2454,8 +2454,8 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
 #endif
 #ifdef __linux__
     "-netdev l2tpv3,id=str,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport]\n"
-    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on/off][,udp=on/off]\n"
-    "         [,cookie64=on/off][,counter][,pincounter][,txcookie=txcookie]\n"
+    "         [,rxsession=rxsession],txsession=txsession[,ipv6=on|off][,udp=on|off]\n"
+    "         [,cookie64=on|off][,counter][,pincounter][,txcookie=txcookie]\n"
     "         [,rxcookie=rxcookie][,offset=offset]\n"
     "                configure a network backend with ID 'str' connected to\n"
     "                an Ethernet over L2TPv3 pseudowire.\n"
@@ -2884,7 +2884,7 @@ SRST
                          -device e1000,netdev=n1,mac=52:54:00:12:34:56 \\
                          -netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
 
-``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
+``-netdev l2tpv3,id=id,src=srcaddr,dst=dstaddr[,srcport=srcport][,dstport=dstport],txsession=txsession[,rxsession=rxsession][,ipv6=on|off][,udp=on|off][,cookie64][,counter][,pincounter][,txcookie=txcookie][,rxcookie=rxcookie][,offset=offset]``
     Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3931)
     is a popular protocol to transport Ethernet (and other Layer 2) data
     frames between two systems. It is present in routers, firewalls and