qemu: fix internal error: NUMA isn't available on this host

If libvirt is compiled without NUMACTL support starting libvirtd
reports a libvirt internal error "NUMA isn't available on this host"
without checking if NUMA support is compiled into the libvirt binaries.
This patch adds the missing NUMA support check to prevent the internal error.
It also includes a check if the cgroup controller cpuset is available before
using it.

The error was noticed when libvirtd was restarted with running domains and
on libvirtd start the qemuConnectCgroup gets called during qemuProcessReconnect.

Signed-off-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>

src/qemu/qemu_cgroup.c

@@ -978,6 +978,10 @@ qemuRestoreCgroupState(virDomainObjPtr vm)
     virBitmapPtr all_nodes;
     virCgroupPtr cgroup_temp = NULL;
 
+    if (!virNumaIsAvailable() ||
+        !virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_CPUSET))
+        return;
+
     if (!(all_nodes = virNumaGetHostMemoryNodeset()))
         goto error;