cifs: avoid redundant calls to disable multichannel

When the server reports query network interface info call
as unsupported following a tree connect, it means that
multichannel is unsupported, even if the server capabilities
report otherwise.

When this happens, cifs_chan_skip_or_disable is called to
disable multichannel on the client. However, we only need
to call this when multichannel is currently setup.

Fixes: f591062b ("cifs: handle servers that still advertise multichannel after disabling")
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/client/smb2pdu.c

@@ -419,7 +419,7 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
 		rc = SMB3_request_interfaces(xid, tcon, false);
 		free_xid(xid);
 
-		if (rc == -EOPNOTSUPP) {
+		if (rc == -EOPNOTSUPP && ses->chan_count > 1) {
 			/*
 			 * some servers like Azure SMB server do not advertise
 			 * that multichannel has been disabled with server