synapticsmst: Correct the callback for progress
synapticsmst: Correct the callback for progress

4a036018 broke the callback progress by putting the wrong device type in.

23:34:11:0715 GLib-GObject invalid cast from 'SynapticsMSTDevice' to 'FuDevice'
23:34:11:0715 Fu  fu_device_set_progress: assertion 'FU_IS_DEVICE (device)' failed

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