scsi: scsi_debug: Fix memleak in scsi_debug_init()

When sdeb_zbc_model does not match BLK_ZONED_NONE, BLK_ZONED_HA or
BLK_ZONED_HM, we should free sdebug_q_arr to prevent memleak. Also there is
no need to execute sdebug_erase_store() on failure of sdeb_zbc_model_str().

Link: https://lore.kernel.org/r/20201226061503.20050-1-dinghao.liu@zju.edu.cnAcked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_debug.c

@@ -6740,7 +6740,7 @@ static int __init scsi_debug_init(void)
 		k = sdeb_zbc_model_str(sdeb_zbc_model_s);
 		if (k < 0) {
 			ret = k;
-			goto free_vm;
+			goto free_q_arr;
 		}
 		sdeb_zbc_model = k;
 		switch (sdeb_zbc_model) {
@@ -6753,7 +6753,8 @@ static int __init scsi_debug_init(void)
 			break;
 		default:
 			pr_err("Invalid ZBC model\n");
-			return -EINVAL;
+			ret = -EINVAL;
+			goto free_q_arr;
 		}
 	}
 	if (sdeb_zbc_model != BLK_ZONED_NONE) {