farsync: remove redundant variable txq_length

Variable txq_length is being assigned but is never used hence it is
redundant and can be removed.

Cleans up clang warning:
warning: variable 'txq_length' set but not used [-Wunused-but-set-variable]

Signed-off-by: Colin Ian King <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/wan/farsync.c

···
 fst_openport(struct fst_port_info *port)
 {
 	int signals;
-	int txq_length;
 
 	/* Only init things if card is actually running. This allows open to
 	 * succeed for downloads etc.
···
 		else
 			netif_carrier_off(port_to_dev(port));
 
-		txq_length = port->txqe - port->txqs;
 		port->txqe = 0;
 		port->txqs = 0;
 	}