Problem:
========
- innodb.temp_truncate_freed fails with ER_WRONG_ARGUMENTS and
states that another buffer pool resize is already in progress.
Test case has wait condition to ensure that buffer pool
resize is completed. There is a possibility that wait condition
check could get false impression that InnoDB buffer pool resize
completed due to previous buffer pool resize.

Fix:
===
Add more elaborate wait_condition to ensure the current buffer
pool resize completed.

buf_pool_t::resize(): Set the buffer pool resize status only
after setting previous buffer pool size to current buffer pool
size. This should help the test case to make reliable.