arm64/numa: remove some useless code

When the deleted code is executed, only the bit of cpu0 was set on
cpu_possible_mask. So that, only set_cpu_numa_node(0, NUMA_NO_NODE); will
be executed. And map_cpu_to_node(0, 0) will soon be called. So these code
can be safely removed.
Signed-off-by: NZhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/mm/numa.c

@@ -95,7 +95,6 @@ void numa_clear_node(unsigned int cpu)
  */
 static void __init setup_node_to_cpumask_map(void)
 {
-	unsigned int cpu;
 	int node;
 
 	/* setup nr_node_ids if not done yet */
@@ -108,9 +107,6 @@ static void __init setup_node_to_cpumask_map(void)
 		cpumask_clear(node_to_cpumask_map[node]);
 	}
 
-	for_each_possible_cpu(cpu)
-		set_cpu_numa_node(cpu, NUMA_NO_NODE);
-
 	/* cpumask_of_node() will now work */
 	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
 }