Correct some comments

In commit aae3f921
recv_apply_hashed_log_recs() was replaced by recv_sys_t::apply().

storage/innobase/include/log0recv.h

 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2020, MariaDB Corporation.
+Copyright (c) 2017, 2021, 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 the Free Software
@@ -214,8 +214,8 @@ struct recv_sys_t
   /** whether recv_recover_page(), invoked from buf_page_read_complete(),
   should apply log records*/
   bool apply_log_recs;
-	/** whether recv_apply_hashed_log_recs() is running */
-	bool		apply_batch_on;
+  /** whether apply() is running */
+  bool apply_batch_on;
 	byte*		buf;	/*!< buffer for parsing log records */
 	ulint		len;	/*!< amount of data in buf */
 	lsn_t		parse_start_lsn;

storage/innobase/srv/srv0start.cc

@@ -1474,8 +1474,7 @@ dberr_t srv_start(bool create_new_db)
 			}
 			/* fall through */
 		case SRV_OPERATION_RESTORE:
-			/* This must precede
-			recv_apply_hashed_log_recs(true). */
+			/* This must precede recv_sys.apply(true). */
 			srv_undo_tablespaces_active
 				= trx_rseg_get_n_undo_tablespaces();
 			err = srv_validate_undo_tablespaces();