Summary

* Move kern_table members out of kernel/sysctl.c

  Moved a subset (tracing, panic, signal, stack_tracer and sparc) out of the
  kern_table array. The goal is for kern_table to only have sysctl elements. All
  this increases modularity by placing the ctl_tables closer to where they are
  used while reducing the chances of merge conflicts in kernel/sysctl.c.

* Fixed sysctl unit test panic by relocating it to selftests

* Testing

  These have been in linux-next from rc2, so they have had more than a month
  worth of testing.

sysctl: Close test ctl_headers with a for loop

As more tests are added, the exit function gets longer than it should
be. Condense the un-register calls into a for loop to make it easier to
add/remove tests.

Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>