qemu: fix guestfwd chardev option back how it was

Since commit d86c876a we are using
guestfwd=tcp:IP:PORT,chardev=ID for guestfwd specification, however,
that has not changed in qemu, so guestfwd does not work since.

Apart from that, guestfwd is not working with older qemu that doesn't
have QEMU_CAPS_DEVICE.

Both regressions exist since late 2009 and nobody found that (until
now), so I'm only fixing the first one.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1112066Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

src/qemu/qemu_command.c

@@ -9186,7 +9186,7 @@ qemuBuildChannelChrDeviceStr(char **deviceStr,
         port = virSocketAddrGetPort(chr->target.addr);
 
         if (virAsprintf(deviceStr,
-                        "user,guestfwd=tcp:%s:%i,chardev=char%s,id=user-%s",
+                        "user,guestfwd=tcp:%s:%i-chardev:char%s,id=user-%s",
                         addr, port, chr->info.alias, chr->info.alias) < 0) {
             virReportOOMError();
             goto cleanup;

tests/qemuxml2argvdata/qemuxml2argv-channel-guestfwd.args

@@ -4,5 +4,5 @@ pc -m 214 -smp 1 -nographic -nodefconfig -nodefaults -chardev socket,\
 id=charmonitor,path=/tmp/test-monitor,server,nowait -mon chardev=charmonitor,\
 id=monitor,mode=readline -no-acpi -boot c -usb -hda /dev/HostVG/QEMUGuest1 -chardev \
 pipe,id=charchannel0,path=/tmp/guestfwd -netdev user,\
-guestfwd=tcp:10.0.2.1:4600,chardev=charchannel0,id=user-channel0 -device \
+guestfwd=tcp:10.0.2.1:4600-chardev:charchannel0,id=user-channel0 -device \
 virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3