The DS driver registers as a subsys_initcall() but this can be too
early, in particular this risks registering before we've had a chance
to allocate and setup module_kset in kernel/params.c which is
performed also as a subsyts_initcall().
Register DS using device_initcall() insteal.
Signed-off-by: David S. Miller <davem@davemloft.net> Cc: stable@vger.kernel.org