Fix the flags argument: M_WAITOK is not a valid flag. Its presence
leaves the indication that contigmalloc(9) will not return a NULL
pointer.
The use of contigmalloc(9) in this place is probably not a good idea
given the constraints. It's probably better to lift the constraints
and instead add a permanent mapping to the ITR. It's possible that
the first 256MB of memory is exhausted when we get here.
This fixes a kernel panic on a 16GB rx3600.
47538c21e5