bpf: use rcu_migrate_* for bpf_iter_run_prog()

Replace the migrate_disable/migrate_enable with
rcu_migrate_disable/rcu_migrate_enable in bpf_iter_run_prog to obtain
better performance when PREEMPT_RCU is not enabled.

Signed-off-by: Menglong Dong <[email protected]>

Author: image-dragon

kernel/bpf/bpf_iter.c

@@ -706,11 +706,11 @@ int bpf_iter_run_prog(struct bpf_prog *prog, void *ctx)
 		rcu_read_unlock_trace();
 	} else {
 		rcu_read_lock();
-		migrate_disable();
+		rcu_migrate_disable();
 		old_run_ctx = bpf_set_run_ctx(&run_ctx);
 		ret = bpf_prog_run(prog, ctx);
 		bpf_reset_run_ctx(old_run_ctx);
-		migrate_enable();
+		rcu_migrate_enable();
 		rcu_read_unlock();
 	}