trivial: quiet the modem manager error about unable to probe
trivial: quiet the modem manager error about unable to probe

We don't show messages in the logs about unable to probe other
device types by default, MM should be no different.
This gets rid of this message coming up every fwupd startup on a
EM05-G:
"failed to probe MM device: modem cannot be put in programming mode"

fwupd/fwupd,fwupd/fwupd,fwupd/fwupd,fwupd/fwupd