cifs: empty interface list when server doesn't support query interfaces

When querying server interfaces returns -EOPNOTSUPP,
clear the list of interfaces. Assumption is that multichannel
would be disabled too.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/smb2ops.c

@@ -717,7 +717,7 @@ SMB3_request_interfaces(const unsigned int xid, struct cifs_tcon *tcon, bool in_
 	if (rc == -EOPNOTSUPP) {
 		cifs_dbg(FYI,
 			 "server does not support query network interfaces\n");
-		goto out;
+		ret_data_len = 0;
 	} else if (rc != 0) {
 		cifs_tcon_dbg(VFS, "error %d on ioctl to get interface list\n", rc);
 		goto out;