mlxsw: core: Fix use-after-free calling devl_unlock() in mlxsw_core_bus_device_unregister()

Do devl_unlock() before freeing the devlink in
mlxsw_core_bus_device_unregister() function.

Reported-by: Ido Schimmel <idosch@nvidia.com>
Fixes: 72a4c8c9 ("mlxsw: convert driver to use unlocked devlink API during init/fini")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20220721142424.3975704-1-jiri@resnulli.us


Signed-off-by: Jakub Kicinski <kuba@kernel.org>