ice: fix clang warning regarding deadcode.DeadStores

clang generates deadcode.DeadStores warnings when a variable
is used to read a value, but then that value isn't used later
in the code. Fix this warning.
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice_ethtool.c

@@ -3501,13 +3501,9 @@ static int
 ice_get_rc_coalesce(struct ethtool_coalesce *ec, enum ice_container_type c_type,
 		    struct ice_ring_container *rc)
 {
-	struct ice_pf *pf;
-
 	if (!rc->ring)
 		return -EINVAL;
 
-	pf = rc->ring->vsi->back;
-
 	switch (c_type) {
 	case ICE_RX_CONTAINER:
 		ec->use_adaptive_rx_coalesce = ITR_IS_DYNAMIC(rc);
@@ -3519,7 +3515,7 @@ ice_get_rc_coalesce(struct ethtool_coalesce *ec, enum ice_container_type c_type,
 		ec->tx_coalesce_usecs = rc->itr_setting;
 		break;
 	default:
-		dev_dbg(ice_pf_to_dev(pf), "Invalid c_type %d\n", c_type);
+		dev_dbg(ice_pf_to_dev(rc->ring->vsi->back), "Invalid c_type %d\n", c_type);
 		return -EINVAL;
 	}