[CIFS] mount option sec=none not displayed properly in /proc/mounts

When the user specifies "sec=none" in a cifs mount, we set
sec_type as unspecified (and set a flag and the username will be
null) rather than setting sectype as "none" so
cifs_show_security was not properly displaying it in
cifs /proc/mounts entries.
Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@poochiereds.net>

fs/cifs/cifsfs.c

@@ -325,8 +325,11 @@ cifs_show_address(struct seq_file *s, struct TCP_Server_Info *server)
 static void
 cifs_show_security(struct seq_file *s, struct cifs_ses *ses)
 {
-	if (ses->sectype == Unspecified)
+	if (ses->sectype == Unspecified) {
+		if (ses->user_name == NULL)
+			seq_puts(s, ",sec=none");
 		return;
+	}
 
 	seq_puts(s, ",sec=");