lib/list_sort: use late_initcall to hook in self tests

This was using module_init, but there is no way this code can
be modular.  In the non-modular case, a module_init becomes a
device_initcall, but this really isn't a device.   So we should
choose a more appropriate initcall bucket to put it in.

Assuming boot time self tests need to be observed over a console
to be useful, and that the console device could possibly not be
fully functional until after device_initcall, we move this to the
late_initcall bucket, which is immediately after device_initcall.

Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>