Revert ds1wm.c from "w1: hold bus_mutex in netlink and search"

This reverts ds1wm.c from commit d3a8a9db.
Of the three files changed ds1wm.c ds2490.c and w1_netlink.c, it turns out
ds1wm.c was locking bus_mutex, but inside the loop and I missed it.
Reverting ds1wm.c to the previous version.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Fries <David@Fries.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>