trivial: Fix a trivial warning in the altos plugin
trivial: Fix a trivial warning in the altos plugin

hughsie/fwupd,hughsie/fwupd,hughsie/fwupd,fwupd/fwupd,fwupd/fwupd,superm1/fwupd,vathpela/fwupd,vathpela/fwupd,vathpela/fwupd,vathpela/fwupd,superm1/fwupd,fwupd/fwupd,superm1/fwupd,fwupd/fwupd,hughsie/fwupd