Fix bug #5414 in 4.1: srv_max_n_threads was always set to only 1000, regardless of the buffer pool size; undelr very high concurrent loads this could cause an assertion failure in sync0arr.c line 384 when we ran out of wait slots for threads; also innodb_thread_concurrency did not work, because the wait queue also there overflowed at 1000 concurrent threads; also remove redundant code
trx0undo.c:
  Add a missing newline to fprints