Depending on the routine, on[e] of the following should be done:

	* replace the return with abort().
	  The hash/md functions should probably have this done.


	* remove the /* XXXLUKEM */ comment; it's ok to return in this
	  case.  I effectively did this for functions which do stuff
	  like free a list; it really doesn't matter if the top-level
	  pointer is checked against NULL because the invoker doesn't
	  care anyway.

I think that depending on context, any of the following may also be
appropriate:

 * For functions which take pointer/length pairs, no longer flag
passing a NULL pointer with a length of zero as an error.

 * Remove the #ifdef _DIAGNOSTIC code entirely, since the hardware
will do adequate NULL pointer checks if the pointer is referenced.

					- Bill