Cleanup: Remove export_vars.innodb_num_open_files

storage/innobase/handler/ha_innodb.cc

@@ -978,7 +978,7 @@ static SHOW_VAR innodb_status_variables[]= {
   {"system_rows_read", &export_vars.innodb_system_rows_read, SHOW_SIZE_T},
   {"system_rows_updated", &export_vars.innodb_system_rows_updated,
    SHOW_SIZE_T},
-  {"num_open_files", &export_vars.innodb_num_open_files, SHOW_SIZE_T},
+  {"num_open_files", &fil_system.n_open, SHOW_SIZE_T},
   {"truncated_status_writes", &export_vars.innodb_truncated_status_writes,
    SHOW_SIZE_T},
   {"available_undo_logs", &srv_available_undo_logs, SHOW_ULONG},

storage/innobase/include/srv0srv.h

@@ -812,7 +812,6 @@ struct export_var_t{
 	ulint innodb_system_rows_inserted; /*!< srv_n_system_rows_inserted */
 	ulint innodb_system_rows_updated; /*!< srv_n_system_rows_updated */
 	ulint innodb_system_rows_deleted; /*!< srv_n_system_rows_deleted*/
-	ulint innodb_num_open_files;		/*!< fil_system_t::n_open */
 	ulint innodb_truncated_status_writes;	/*!< srv_truncated_status_writes */
 
 	/** Number of undo tablespace truncation operations */

storage/innobase/srv/srv0srv.cc

@@ -1225,8 +1225,6 @@ srv_export_innodb_status(void)
 	export_vars.innodb_system_rows_deleted =
 		srv_stats.n_system_rows_deleted;
 
-	export_vars.innodb_num_open_files = fil_system.n_open;
-
 	export_vars.innodb_truncated_status_writes =
 		srv_truncated_status_writes;