sfc: PTP - tidy up unused/useless variables

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index be7ed4e..82d8e27 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -237,9 +237,6 @@
  * @evt_code: Last event code
  * @start: Address at which MC indicates ready for synchronisation
  * @host_time_pps: Host time at last PPS
- * @last_sync_ns: Last number of nanoseconds between readings when synchronising
- * @base_sync_ns: Number of nanoseconds for last synchronisation.
- * @base_sync_valid: Whether base_sync_time is valid.
  * @current_adjfreq: Current ppb adjustment.
  * @phc_clock: Pointer to registered phc device
  * @phc_clock_info: Registration structure for phc device
@@ -274,9 +271,6 @@
 	int evt_code;
 	struct efx_buffer start;
 	struct pps_event_time host_time_pps;
-	unsigned last_sync_ns;
-	unsigned base_sync_ns;
-	bool base_sync_valid;
 	s64 current_adjfreq;
 	struct ptp_clock *phc_clock;
 	struct ptp_clock_info phc_clock_info;
@@ -482,18 +476,10 @@
 
 	if (ngood == 0) {
 		netif_warn(efx, drv, efx->net_dev,
-			   "PTP no suitable synchronisations %dns\n",
-			   ptp->base_sync_ns);
+			   "PTP no suitable synchronisations\n");
 		return -EAGAIN;
 	}
 
-	/* Average minimum this synchronisation */
-	ptp->last_sync_ns = DIV_ROUND_UP(total, ngood);
-	if (!ptp->base_sync_valid || (ptp->last_sync_ns < ptp->base_sync_ns)) {
-		ptp->base_sync_valid = true;
-		ptp->base_sync_ns = ptp->last_sync_ns;
-	}
-
 	/* Calculate delay from actual PPS to last_time */
 	delta.tv_nsec =
 		ptp->timeset[last_good].nanoseconds +