an7581/base-files: use IPKG_INSTROOT when sourcing functions.sh

* fixes the following error message when using image builder to create an
  image for an7581 devices:

build_dir/target-aarch64_cortex-a53_musl/root-airoha/etc/init.d/airoha_fan: line 8: /lib/functions.sh: No such file or directory

Signed-off-by: Stan Grishin <stangri@melmac.ca>
Link: https://github.com/openwrt/openwrt/pull/23814
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>

diff --git a/target/linux/airoha/an7581/base-files/etc/init.d/airoha_fan b/target/linux/airoha/an7581/base-files/etc/init.d/airoha_fan
index d30205f546b040f800350e5dd560fd44960f569e..b9d5633bd1a4bbfb3cc4ad1d6df4c1d9d1b6ca0f 100755 (executable)
--- a/target/linux/airoha/an7581/base-files/etc/init.d/airoha_fan
+++ b/target/linux/airoha/an7581/base-files/etc/init.d/airoha_fan
@@ -5,7 +5,7 @@
 
 START=99
 
-. /lib/functions.sh
+. "$IPKG_INSTROOT/lib/functions.sh"
 
 find_nct7802()
 {