packet: remove deprecated syststamp timestamp

No device driver will ever return an skb_shared_info structure with
syststamp non-zero, so remove the branch that tests for this and
optionally marks the packet timestamp as TP_STATUS_TS_SYS_HARDWARE.

Do not remove the definition TP_STATUS_TS_SYS_HARDWARE, as processes
may refer to it.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 614ca91..8d9f804 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -441,14 +441,10 @@
 {
 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 
-	if (shhwtstamps) {
-		if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
-		    ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
-			return TP_STATUS_TS_SYS_HARDWARE;
-		if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
-		    ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
-			return TP_STATUS_TS_RAW_HARDWARE;
-	}
+	if (shhwtstamps &&
+	    (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+	    ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
+		return TP_STATUS_TS_RAW_HARDWARE;
 
 	if (ktime_to_timespec_cond(skb->tstamp, ts))
 		return TP_STATUS_TS_SOFTWARE;