Clean up InnoDB shutdown

Tablespace::shutdown(): Clear m_path. This was moved from
Tablespace::~Tablespace().

LatchDebug::shutdown(): Remove a redundant condition.

storage/innobase/fsp/fsp0space.cc

@@ -65,7 +65,8 @@ Tablespace::shutdown()
 	}
 
 	m_files.clear();
-
+	ut_free(m_path);
+	m_path = NULL;
 	m_space_id = ULINT_UNDEFINED;
 }
 

storage/innobase/include/fsp0space.h

@@ -62,10 +62,6 @@ class Tablespace {
 		shutdown();
 		ut_ad(m_files.empty());
 		ut_ad(m_space_id == ULINT_UNDEFINED);
-		if (m_path != NULL) {
-			ut_free(m_path);
-			m_path = NULL;
-		}
 	}
 
 	// Disable copying

storage/innobase/srv/srv0start.cc

@@ -2788,11 +2788,7 @@ innodb_shutdown()
 	ut_ad(!srv_running);
 	ut_ad(!srv_undo_sources);
 
-	/* 1. Flush the buffer pool to disk, write the current lsn to
-	the tablespace header(s), and copy all log data to archive.
-	The step 1 is the real InnoDB shutdown. The remaining steps 2 - ...
-	just free data structures after the shutdown. */
-
+	/* Shut down the persistent files. */
 	logs_empty_and_mark_files_at_shutdown();
 
 	if (ulint n_threads = srv_conc_get_active_threads()) {
@@ -2801,7 +2797,7 @@ innodb_shutdown()
 			" inside InnoDB at shutdown";
 	}
 
-	/* 2. Make all threads created by InnoDB to exit */
+	/* Exit any remaining threads. */
 	srv_shutdown_all_bg_threads();
 
 	if (srv_monitor_file) {

storage/innobase/sync/sync0debug.cc

@@ -1267,11 +1267,6 @@ LatchDebug::shutdown()
 
 	mutex_free(&rw_lock_debug_mutex);
 
-	if (instance() == NULL) {
-
-		return;
-	}
-
 	ut_a(s_initialized);
 
 	s_initialized = false;