drivers: net: lmc: remove redundant variable next_rx

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

Cleans up clang warning:
warning: variable 'next_rx' set but not used [-Wunused-but-set-variable]
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/wan/lmc/lmc_main.c

@@ -1491,7 +1491,6 @@ static int lmc_rx(struct net_device *dev)
     lmc_softc_t *sc = dev_to_sc(dev);
     int i;
     int rx_work_limit = LMC_RXDESCS;
-    unsigned int next_rx;
     int rxIntLoopCnt;		/* debug -baz */
     int localLengthErrCnt = 0;
     long stat;
@@ -1505,7 +1504,6 @@ static int lmc_rx(struct net_device *dev)
     rxIntLoopCnt = 0;		/* debug -baz */
 
     i = sc->lmc_next_rx % LMC_RXDESCS;
-    next_rx = sc->lmc_next_rx;
 
     while (((stat = sc->lmc_rxring[i].status) & LMC_RDES_OWN_BIT) != DESC_OWNED_BY_DC21X4)
     {