Eliminate get_driver() and put_driver()

Now that there are no users of get_driver() or put_driver(), this
patch (as1513) removes those routines completely.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>