fujitsu-laptop: remove superfluous NULL pointer checks

This takes care of the following entries from Dan's list:

drivers/platform/x86/fujitsu-laptop.c +327 set_lcd_level(13) warning:
variable derefenced before check 'fujitsu'
drivers/platform/x86/fujitsu-laptop.c +358 set_lcd_level_alt(13) warning:
variable derefenced before check 'fujitsu'

Reported-by: Dan Carpenter <error27@gmail.com>
Cc: corbet@lwn.net
Cc: eteo@redhat.com
Cc: Julia Lawall <julia@diku.dk>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>