ACPI: NUMA: Optimize the check for the availability of node values

The first_unset_node() function returns the first unused node in
nodes_found_map. If all nodes are in use, the function returns
MAX_NUMNODES.

Use this return value to determine whether there are any available node
values in nodes_found_map, eliminating the need to use nodes_weight()
for this purpose.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/numa/srat.c

@@ -67,9 +67,9 @@ int acpi_map_pxm_to_node(int pxm)
 	node = pxm_to_node_map[pxm];
 
 	if (node == NUMA_NO_NODE) {
-		if (nodes_weight(nodes_found_map) >= MAX_NUMNODES)
-			return NUMA_NO_NODE;
 		node = first_unset_node(nodes_found_map);
+		if (node >= MAX_NUMNODES)
+			return NUMA_NO_NODE;
 		__acpi_map_pxm_to_node(pxm, node);
 		node_set(node, nodes_found_map);
 	}