ocfs2: Remove masklog ML_AIO.

There is no user for masklog AIO, so remove it.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>

fs/ocfs2/cluster/masklog.c

@@ -91,7 +91,6 @@ static struct mlog_attribute mlog_attrs[MLOG_MAX_BITS] = {
 	define_mask(DLM_THREAD),
 	define_mask(DLM_MASTER),
 	define_mask(DLM_RECOVERY),
-	define_mask(AIO),
 	define_mask(DLM_GLUE),
 	define_mask(VOTE),
 	define_mask(CONN),

fs/ocfs2/cluster/masklog.h

@@ -93,7 +93,6 @@
 #define ML_DLM_THREAD	0x0000000000000400ULL /* dlm domain thread */
 #define ML_DLM_MASTER	0x0000000000000800ULL /* dlm master functions */
 #define ML_DLM_RECOVERY	0x0000000000001000ULL /* dlm master functions */
-#define ML_AIO		0x0000000000002000ULL /* ocfs2 aio read and write */
 #define ML_DLM_GLUE	0x0000000000080000ULL /* ocfs2 dlm glue layer */
 #define ML_VOTE		0x0000000001000000ULL /* ocfs2 node messaging  */
 #define ML_CONN		0x0000000004000000ULL /* net connection management */