gve: report 64bit tx_bytes counter from gve_handle_report_stats()

Each tx queue maintains a 64bit counter for bytes, there is
no reason to truncate this to 32bit (or this has not been
documented)

Fixes: 24aeb56f ("gve: Add Gvnic stats AQ command and ethtool show/set-priv-flags.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yangchun Fu <yangchun@google.com>
Cc: Kuo Zhao <kuozhao@google.com>
Cc: David Awogbemila <awogbemila@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/google/gve/gve_main.c

@@ -1197,9 +1197,10 @@ static void gve_handle_reset(struct gve_priv *priv)
 
 void gve_handle_report_stats(struct gve_priv *priv)
 {
-	int idx, stats_idx = 0, tx_bytes;
-	unsigned int start = 0;
 	struct stats *stats = priv->stats_report->stats;
+	int idx, stats_idx = 0;
+	unsigned int start = 0;
+	u64 tx_bytes;
 
 	if (!gve_get_report_stats(priv))
 		return;