Bug#1085850: regression: bluetooth game controller no longer connects

[Forest <forestix@nom.one>]

Control: tags -1 - moreinfo

I still don't know any examples of an unpaired bluetooth device triggering
dmesg entries at boot time.  (If this ever happens with any such device, I
would be interested in knowing how and why.)

But since you asked, I tried it anyway.  The device enters pairing mode as
soon as I press the wake button, and goes back to sleep if not paired after
several seconds, so I had to carefully synchronize it with choosing a boot
entry in GRUB.  As expected, dmesg | grep -E '( bt)|bluetooth' yielded
nothing interesting.  So btusb (the module affected by 2c1dda2acc41) was
apparently not complaining.