trivial: thunderbolt: don't set update error for missing nvmem
trivial: thunderbolt: don't set update error for missing nvmem

Trying to explain why ICL thunderbolt isn't updatable doesn't help
people.  It just causes fwupdmgr and fwupdtool to show the device
front and center with a confusing message.

Instead don't populate the message and by the default device filter
it will be hidden.

See #2212 for background.

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