return DB_CORRUPTION (HA_ERR_CRASHED) instead of abnormally
terminating the server.  Also, disable the previously added diagnostic
output to the error log, because mysql-test-run does not like extra
output in the error log.  (Bug #44571)

dict_index_add_to_cache(): Handle errors from dict_index_find_cols().

mysql-test/innodb_bug44571.test: A test case for triggering the bug.

rb://135 approved by Sunny Bains.