The problem was that the test was trying to obtain a lock on
a table in one connection without ensuring that a insert which
was executed in another connection had released the lock on the
same table.

The solution is to add a dummy select query after the insert to
ensure that the table is unlocked and closed by the time it tries
to lock it again. This is enough to prevent test failures described
in the bug report. As an extra safety measure, concurrent inserts
are disabled.

Remove comments that calculated the Table_locks_immediate. This
value is not tested anymore and it's calculation did not reflect
the actual value.

mysql-test/r/status.result:
  Update test case result.
mysql-test/t/status.test:
  Issue a dummy select to ensure that tables are unlocked after a
  insert and disable concurrent inserts as a extra-safety.