cifs: minor update to comments around the cifs_tcp_ses_lock mutex

Update comment to note that it protects server->dstaddr
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsglob.h

@@ -1891,7 +1891,8 @@ GLOBAL_EXTERN struct list_head		cifs_tcp_ses_list;
 /*
  * This lock protects the cifs_tcp_ses_list, the list of smb sessions per
  * tcp session, and the list of tcon's per smb session. It also protects
- * the reference counters for the server, smb session, and tcon. Finally,
+ * the reference counters for the server, smb session, and tcon. It also
+ * protects some fields in the TCP_Server_Info struct such as dstaddr. Finally,
  * changes to the tcon->tidStatus should be done while holding this lock.
  * generally the locks should be taken in order tcp_ses_lock before
  * tcon->open_file_lock and that before file->file_info_lock since the