vl.c: Don't limit node count by smp count

[I've sent this patch couple of months ago and noticed it
 didn't make it's way in - so I'm sending it again]

It is possible to create CPU-less NUMA nodes, node amount shouldn't be
limited by amount of CPUs.
Tested-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: NAndre Przywara <andre.przywara@amd.com>
Signed-off-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

vl.c

@@ -3129,8 +3129,8 @@ int main(int argc, char **argv, char **envp)
     if (nb_numa_nodes > 0) {
         int i;
 
-        if (nb_numa_nodes > smp_cpus) {
-            nb_numa_nodes = smp_cpus;
+        if (nb_numa_nodes > MAX_NODES) {
+            nb_numa_nodes = MAX_NODES;
         }
 
         /* If no memory size if given for any node, assume the default case