MDEV-32050 fixup: Remove srv_purge_rseg_truncate_frequency

storage/innobase/handler/ha_innodb.cc

@@ -19349,8 +19349,10 @@ static MYSQL_SYSVAR_ULONGLONG(max_undo_log_size, srv_max_undo_log_size,
   10 << 20, 10 << 20,
   1ULL << (32 + UNIV_PAGE_SIZE_SHIFT_MAX), 0);
 
+static ulong innodb_purge_rseg_truncate_frequency;
+
 static MYSQL_SYSVAR_ULONG(purge_rseg_truncate_frequency,
-  srv_purge_rseg_truncate_frequency,
+  innodb_purge_rseg_truncate_frequency,
   PLUGIN_VAR_OPCMDARG | PLUGIN_VAR_DEPRECATED,
   "Deprecated parameter with no effect",
   NULL, NULL, 128, 1, 128, 0);

storage/innobase/include/srv0srv.h

@@ -263,9 +263,6 @@ extern unsigned long long	srv_max_undo_log_size;
 extern uint	srv_n_fil_crypt_threads;
 extern uint	srv_n_fil_crypt_threads_started;
 
-/** Rate at which UNDO records should be purged. */
-extern ulong	srv_purge_rseg_truncate_frequency;
-
 /** Enable or Disable Truncate of UNDO tablespace. */
 extern my_bool	srv_undo_log_truncate;
 

storage/innobase/srv/srv0srv.cc

@@ -107,9 +107,6 @@ segment). It is quite possible that some of the tablespaces doesn't host
 any of the rollback-segment based on configuration used. */
 ulint	srv_undo_tablespaces_active;
 
-/** Rate at which UNDO records should be purged. */
-ulong	srv_purge_rseg_truncate_frequency;
-
 /** Enable or Disable Truncate of UNDO tablespace.
 Note: If enabled then UNDO tablespace will be selected for truncate.
 While Server waits for undo-tablespace to truncate if user disables