net: drivers: use bool type instead of double negation

Save some punctuation by using bool type's property equivalent to
doubled negation operator.

Reported-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/jme.c b/drivers/net/ethernet/jme.c
index df3ab83..5c0b531 100644
--- a/drivers/net/ethernet/jme.c
+++ b/drivers/net/ethernet/jme.c
@@ -1883,7 +1883,7 @@
 		struct page *page,
 		u32 page_offset,
 		u32 len,
-		u8 hidma)
+		bool hidma)
 {
 	dma_addr_t dmaaddr;
 
@@ -1917,7 +1917,7 @@
 	struct jme_ring *txring = &(jme->txring[0]);
 	struct txdesc *txdesc = txring->desc, *ctxdesc;
 	struct jme_buffer_info *txbi = txring->bufinf, *ctxbi;
-	u8 hidma = !!(jme->dev->features & NETIF_F_HIGHDMA);
+	bool hidma = jme->dev->features & NETIF_F_HIGHDMA;
 	int i, nr_frags = skb_shinfo(skb)->nr_frags;
 	int mask = jme->tx_ring_mask;
 	const struct skb_frag_struct *frag;