s390/dasd: Use kzalloc instead of kmalloc/memset

Use kzalloc rather than duplicating its implementation, which
makes code simple and easy to understand.

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
Link: https://lore.kernel.org/r/20220505141733.1989450-6-sth@linux.ibm.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Lotte-Bai

drivers/s390/block/dasd_eckd.c

@@ -1480,17 +1480,14 @@ static int dasd_eckd_pe_handler(struct dasd_device *device,
 {
 	struct pe_handler_work_data *data;
 
-	data = kmalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
+	data = kzalloc(sizeof(*data), GFP_ATOMIC | GFP_DMA);
 	if (!data) {
 		if (mutex_trylock(&dasd_pe_handler_mutex)) {
 			data = pe_handler_worker;
 			data->isglobal = 1;
 		} else {
 			return -ENOMEM;
 		}
-	} else {
-		memset(data, 0, sizeof(*data));
-		data->isglobal = 0;
 	}
 	INIT_WORK(&data->worker, do_pe_handler_work);
 	dasd_get_device(device);