dfu: Fix a potential buffer overflow when applying a patch
dfu: Fix a potential buffer overflow when applying a patch

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