How to reproduce:
1. enable changelog
2. on client, write c code which calls
setxattr("filename", "system.posix_acl_default", val, 0, 0);
in a loop.
3. run the c code, make sure it's the only op issued to mds.

osd_trans_exec_op() will complain.

We should declare changelog store for system.posix_acl_default and system.posix_acl_access.