md: changed the switch of RAID_VERSION to if

There is only one case of this 'switch'. Change it to 'if'.
Signed-off-by: Li Nan <linan122@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240226031444.3606764-3-linan666@huaweicloud.com

drivers/md/md.c

@@ -7613,12 +7613,8 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
 	 * Commands dealing with the RAID driver but not any
 	 * particular array:
 	 */
-	switch (cmd) {
-	case RAID_VERSION:
-		err = get_version(argp);
-		goto out;
-	default:;
-	}
+	if (cmd == RAID_VERSION)
+		return get_version(argp);
 
 	/*
 	 * Commands creating/starting a new array: