show engine tokudb logs always reports nothing.  the tokudb log_archhive function always returns EINVAL since it does not support flags!=0.  set log_archive flags=0 for tokudb to avoid EINVAL return.  addresses #697



git-svn-id: file:///svn/mysql/tokudb-engine/src@3450 c7de825b-a66e-492c-adef-691d508d4ae1