cleanups

storage/maria/ma_commit.c:
  theoretically unneeded, and could cause problems (when trnman_commit_trn()
  ends the TRN may have been recycled and be in use by another thread
  already, we cannot touch it).
storage/maria/maria_def.h:
  just include the existing file

storage/maria/ma_commit.c

@@ -67,7 +67,6 @@ int ma_commit(TRN *trn)
                               log_array, NULL) ||
         translog_flush(commit_lsn) ||
         trnman_commit_trn(trn));
-  trn->undo_lsn= 0;
   /*
     Note: if trnman_commit_trn() fails above, we have already
     written the COMMIT record, so Checkpoint and Recovery will see the

storage/maria/maria_def.h

@@ -894,7 +894,7 @@ void _ma_restore_status(void *param);
 void _ma_copy_status(void *to, void *from);
 my_bool _ma_check_status(void *param);
 void _ma_reset_status(MARIA_HA *maria);
-int ma_commit(struct st_transaction *trn);
+#include "ma_commit.h"
 
 extern MARIA_HA *_ma_test_if_reopen(char *filename);
 my_bool _ma_check_table_is_closed(const char *name, const char *where);