ath79: set lzma-loader variables to null by default

This fixes a small regression where the lzma-loader variable values
are being shared between boards that require different configurations.

If not set to "" globally, a device without these settings will just take
the last values another device has set before in the queue.

Fixes: 1b8bd17c2d07 ("ath79: lzma-loader: allow setting custom kernel magic")
Signed-off-by: Michael Pratt <mcpratt@pm.me>
[add detailed explanation to the commit message]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
(cherry picked from commit bf8c16dfa2cddd529f889510ca5fa5160606c325)

diff --git a/target/linux/ath79/image/Makefile b/target/linux/ath79/image/Makefile
index d8b8800d91dfe332c90a9ddc695ce24af3a27676..3c126f479e1bc0b8a5eec1d5b02d00947fc199f4 100644 (file)
--- a/target/linux/ath79/image/Makefile
+++ b/target/linux/ath79/image/Makefile
@@ -70,6 +70,10 @@ define Device/Default
   BLOCKSIZE := 64k
   KERNEL := kernel-bin | append-dtb | lzma | uImage lzma
   KERNEL_INITRAMFS := kernel-bin | append-dtb | lzma | uImage lzma
+  LOADER_KERNEL_MAGIC :=
+  LOADER_FLASH_MAX :=
+  LOADER_FLASH_OFFS :=
+  LOADER_TYPE :=
   COMPILE :=
   IMAGES := sysupgrade.bin
   IMAGE/sysupgrade.bin = append-kernel | pad-to $$$$(BLOCKSIZE) | \