Fix panic in run_timer_softirq right after "modprobe -r firewire-ohci"
if a FireWire disk was attached and firewire-sbp2 loaded.

Same as commit 8a2d9ed3.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>