The isc_mempool_create() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_mempool_create() now returns void.
- some of these tests are obsolete and should be cleared up,
others overlap with ATF tests and may be removed later.
for now, let's just tidy up the bin/tests directory by
moving these files down a level.
