drbd: Endianness convert the constants instead of the variables

Converting the constants happens at compile time.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_actlog.c

@@ -407,7 +407,7 @@ static int drbd_al_read_tr(struct drbd_conf *mdev,
 	if (!drbd_md_sync_page_io(mdev, bdev, sector, READ))
 		return -1;
 
-	rv = (be32_to_cpu(b->magic) == DRBD_MAGIC);
+	rv = (b->magic == cpu_to_be32(DRBD_MAGIC));
 
 	for (i = 0; i < AL_EXTENTS_PT + 1; i++)
 		xor_sum ^= be32_to_cpu(b->updates[i].extent);

drivers/block/drbd/drbd_main.c

@@ -3729,7 +3729,7 @@ int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev)
 		goto err;
 	}
 
-	if (be32_to_cpu(buffer->magic) != DRBD_MD_MAGIC) {
+	if (buffer->magic != cpu_to_be32(DRBD_MD_MAGIC)) {
 		dev_err(DEV, "Error while reading metadata, magic not found.\n");
 		rv = ERR_MD_INVALID;
 		goto err;