dell-laptop: Don't set sw_state from the query callback

The query callback should only update the hw_state, see the comment in
net/rfkill/core.c in rfkill_set_block, which is its only caller.

rfkill_set_block will modify the sw_state directly after calling query so
calling set_sw_state is an expensive NOP.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>