[KJ] FIx kernel build warnings

[David Farning]

I am interested in working on some kj projects.

First, I thought that I would look at fixing some of the compile
warning.
TODO LIST 
<snip>
- Fix gcc 4 warnings.
  [D: http://marc.theaimsgroup.com/?t=110348353800003]
  Note: Set CONFIG_DEBUG_INFO=n to make compiles faster and smaller.

The thread link looks pretty old.  Which version of gcc should the kernel be compiled against.

David Farning