qemu.conf: Mention virtlockd in @lock_manager description

When I played with virtlockd I was stunned by lacking
documentation. My frustration got bigger when I had to
read the patches to get the correct value to set in
qemu.conf.

Moreover, from pure libvirt-pride  I'm changing commented
value from sanlock to lockd. We want to favor our own
implementation after all.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu.conf

@@ -402,11 +402,13 @@
 #allow_disk_format_probing = 1
 
 
-# To enable 'Sanlock' project based locking of the file
-# content (to prevent two VMs writing to the same
-# disk), uncomment this
+# In order to prevent accidentally starting two domains that
+# share one writable disk, libvirt offers two approaches for
+# locking files. The first one is sanlock, the other one,
+# virtlockd, is then our own implementation. Accepted values
+# are "sanlock" and "lockd".
 #
-#lock_manager = "sanlock"
+#lock_manager = "lockd"
 
 
 

src/qemu/test_libvirtd_qemu.aug.in

@@ -64,7 +64,7 @@ module Test_libvirtd_qemu =
 { "mac_filter" = "1" }
 { "relaxed_acs_check" = "1" }
 { "allow_disk_format_probing" = "1" }
-{ "lock_manager" = "sanlock" }
+{ "lock_manager" = "lockd" }
 { "max_queued" = "0" }
 { "keepalive_interval" = "5" }
 { "keepalive_count" = "5" }