powerpc/numa: check error return from proc_create

proc_create can fail, we should check the return value and pass up the
failure.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/mm/numa.c

@@ -1801,7 +1801,8 @@ static const struct file_operations topology_ops = {
 static int topology_update_init(void)
 {
 	start_topology_update();
-	proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops);
+	if (!proc_create("powerpc/topology_updates", 0644, NULL, &topology_ops))
+		return -ENOMEM;
 
 	return 0;
 }