sony-laptop - fix using of uninitialized variable

CC [M]  drivers/platform/x86/sony-laptop.o
drivers/platform/x86/sony-laptop.c: In function 'sony_nc_rfkill_setup':
drivers/platform/x86/sony-laptop.c:1162: warning: 'i' may be used uninitialized in this function

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>