Misc. cleanups
- XdmcpCopyARRAY8: Use memcpy() instead of memmove() when buffers are known not to overlap
- arc4random_buf: Only declare ret if HAVE_GETENTROPY is defined (clears unused variable warning from cppcheck)
- XdmcpDisposeARRAYofARRAY8: Reduce scope of i (as suggested by cppcheck)