gve: Correct available tx qpl check

The qpl_map_size is rounded up to a multiple of sizeof(long), but the
number of qpls doesn't have to be.

Fixes: f5cedc84 ("gve: Add transmit and receive support")
Signed-off-by: Catherine Sullivan <csully@google.com>
Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/google/gve/gve.h

@@ -780,7 +780,7 @@ struct gve_queue_page_list *gve_assign_rx_qpl(struct gve_priv *priv)
 				    gve_num_tx_qpls(priv));
 
 	/* we are out of rx qpls */
-	if (id == priv->qpl_cfg.qpl_map_size)
+	if (id == gve_num_tx_qpls(priv) + gve_num_rx_qpls(priv))
 		return NULL;
 
 	set_bit(id, priv->qpl_cfg.qpl_id_map);