lxcStateInitialize: Don't leak driver's caps

Funny thing. So when initializing LXC driver's capabilities,
firstly the virLXCDriverGetCapabilities() is called. This creates
new capabilities, stores them under driver->caps, ref() them and
return them. However, the return value is ignored. Secondly, the
function is called yet again and since we have driver->caps set,
they are ref()-ed again an returned. So in the end, driver's
capabilities have refcount of three when in fact they should have
refcount of one.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/lxc/lxc_driver.c

@@ -1660,7 +1660,7 @@ static int lxcStateInitialize(bool privileged,
     if (!(lxc_driver->hostdevMgr = virHostdevManagerGetDefault()))
         goto cleanup;
 
-    if ((virLXCDriverGetCapabilities(lxc_driver, true)) == NULL)
+    if (!(caps = virLXCDriverGetCapabilities(lxc_driver, true)))
         goto cleanup;
 
     if (!(lxc_driver->xmlopt = lxcDomainXMLConfInit()))
@@ -1669,9 +1669,6 @@ static int lxcStateInitialize(bool privileged,
     if (!(lxc_driver->closeCallbacks = virCloseCallbacksNew()))
         goto cleanup;
 
-    if (!(caps = virLXCDriverGetCapabilities(lxc_driver, false)))
-        goto cleanup;
-
     if (virFileMakePath(cfg->stateDir) < 0) {
         virReportSystemError(errno,
                              _("Failed to mkdir %s"),
@@ -1700,6 +1697,7 @@ static int lxcStateInitialize(bool privileged,
         goto cleanup;
 
     virNWFilterRegisterCallbackDriver(&lxcCallbackDriver);
+    virObjectUnref(caps);
     return 0;
 
  cleanup: