burstsort_mkq.cpp: fix burstsort_mkq_recursiveburst routine
burstsort_mkq.cpp: fix burstsort_mkq_recursiveburst routine

Fix burstsort_mkq_recursiveburst routine: after recursive bursting, we
would access out-of-date entries from the oracle array. To fix it,
refresh the oracle when it is needed.

Thanks to Timo Bingmann <tbgit@panthema.net> for noticing the problem:
https://github.com/bingmann/parallel-string-sorting/commit/cfd3de7bd0284e8ef927804d1c92a7dfeb18ded9

rantala/string-sorting,rantala/string-sorting,rantala/string-sorting,rantala/string-sorting