trivial: Relax the timing requirements on the FuDevice poll test
trivial: Relax the timing requirements on the FuDevice poll test

If the poll source is scheduled just at the right time, we might only get 8x
'10ms ticks' in a 100ms window. This fixes an occasional build failure on
slower hardware and in CI.

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