Make /proc/i8k display '?' when service tag is blank in BIOS.
This fixes segfault in i8k gkrellm plugin.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>