trivial: Also fuzz the CRC checking routines
trivial: Also fuzz the CRC checking routines

At the moment these sections are all red in the coverage report.

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