USB: OHCI: remove obsolete FIXME comment

This comment has been present since the start of git.  Since no one is
going to do anything about it, and all seems to work well, just drop the
thing entirely.

Cc: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20200618094300.1887727-4-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>