w1: ds2482: cosmetic fixes after 54865314

We have a helper function ds2482_calculate_config() which is calculating
the config value, so just use it instead of passing the same variable
in all calls to this function.

Also fixes the placement of module parameters to match with:
50fa2951 (w1: Organize driver source to natural/common order)
by Andrew F. Davis

Signed-off-by: Mariusz Bialonczyk <manio@skyboo.net>
Cc: Andrew Worsley <amworsley@gmail.com>
Cc: Andrew F. Davis <afd@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>