CONFIG_SECURITY=y and CONFIG_SYSFS=n results in the following compile
error:

<--  snip  -->

...
  LD      vmlinux
security/built-in.o: In function `securityfs_init':
inode.c:(.init.text+0x1c2): undefined reference to `kernel_subsys'
make: *** [vmlinux] Error 1

<--  snip  -->
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Chris Wright <chrisw@osdl.org>