Remove the unused function maria_clone

include/maria.h

 /* Copyright (C) 2006-2008 MySQL AB, 2008-2009 Sun Microsystems, Inc.
-   Copyright (c) 2009, 2013, Monty Program Ab.
+   Copyright (c) 2009, 2019, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -286,7 +286,6 @@ extern int maria_close(MARIA_HA *file);
 extern int maria_delete(MARIA_HA *file, const uchar *buff);
 extern MARIA_HA *maria_open(const char *name, int mode,
 					uint wait_if_locked);
-extern MARIA_HA *maria_clone(struct st_maria_share *share, int mode);
 extern int maria_panic(enum ha_panic_function function);
 extern int maria_rfirst(MARIA_HA *file, uchar *buf, int inx);
 extern int maria_rkey(MARIA_HA *file, uchar *buf, int inx,

storage/maria/ma_open.c

 /* Copyright (C) 2006 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+   Copyright (c) 2009, 2019, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -249,20 +250,6 @@ static MARIA_HA *maria_clone_internal(MARIA_SHARE *share,
 } /* maria_clone_internal */
 
 
-/* Make a clone of a maria table */
-
-MARIA_HA *maria_clone(MARIA_SHARE *share, int mode)
-{
-  MARIA_HA *new_info;
-  mysql_mutex_lock(&THR_LOCK_maria);
-  new_info= maria_clone_internal(share, mode,
-                                 share->data_file_type == BLOCK_RECORD ?
-                                 share->bitmap.file.file : -1, 0);
-  mysql_mutex_unlock(&THR_LOCK_maria);
-  return new_info;
-}
-
-
 /******************************************************************************
   open a MARIA table