Replace local array size calculations with NELEM().
Sweep-fix comparing pointers with 0 (and assigning 0 to pointers).For better readability, don't compare pointers with 0 or assign 0to them. Use NULL instead.The change was done with coccinelle.
dfregress,tbridge - Move into usr.bin and sys/dev * cleanup of the testcases, remove duplicates, consolidate in test/testcases.