dm crypt: Make use of the helper macro kthread_run()

Replace kthread_create/wake_up_process() with kthread_run()
to simplify the code.

Signed-off-by: Cai Huoqing <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

Author: caihuoqing1990

drivers/md/dm-crypt.c

@@ -3362,14 +3362,13 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	spin_lock_init(&cc->write_thread_lock);
 	cc->write_tree = RB_ROOT;
 
-	cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
+	cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
 	if (IS_ERR(cc->write_thread)) {
 		ret = PTR_ERR(cc->write_thread);
 		cc->write_thread = NULL;
 		ti->error = "Couldn't spawn write thread";
 		goto bad;
 	}
-	wake_up_process(cc->write_thread);
 
 	ti->num_flush_bios = 1;
 	ti->limit_swap_bios = true;