The sysupgrade_pre_upgrade hook was removed with 5e1b4c57de ("base-files:
drop fwtool_pre_upgrade") while there were still scripts using it:
* target/linux/ar71xx/base-files/lib/upgrade/allnet.sh
* target/linux/ar71xx/base-files/lib/upgrade/openmesh.sh
* target/linux/ipq40xx/base-files/lib/upgrade/openmesh.sh
Not running the hooks can either prevent a successful upgrade or brick the
device because the fw_setenv program cannot be started correctly.
Instead of adding this hook again, the directory /var/lock for fw_setenv
can also just be created directly before fw_setenv is called.
Fixes: 5e1b4c57de ("base-files: drop fwtool_pre_upgrade")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>