Fix error when kernel size is greater than slab thickness.

If the kernel size was larger than the number of slices in the slab
that was being interpolated, then there was a potential for incorrect
results under certain circumstances.

Change-Id: I832f34fc1d4750d494d996e825cf1b2708a9d3dd
Merge topic 'interpolator-kernel-fix' into master

8749c2fe Fix error when kernel size is greater than slab thickness.