tty: Convert use of __constant_htons to htons

In little endian cases, macro htons unfolds to __swab16 which
provides special case for constants. In big endian cases,
__constant_htons and htons expand directly to the same expression.
So, replace __constant_htons with htons with the goal of getting
rid of the definition of __constant_htons completely.

The semantic patch that performs this transformation is as follows:

@@expression x;@@

- __constant_htons(x)
+ htons(x)

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/n_gsm.c

@@ -2712,7 +2712,7 @@ static void gsm_mux_rx_netchar(struct gsm_dlci *dlci,
 	memcpy(skb_put(skb, size), in_buf, size);
 
 	skb->dev = net;
-	skb->protocol = __constant_htons(ETH_P_IP);
+	skb->protocol = htons(ETH_P_IP);
 
 	/* Ship it off to the kernel */
 	netif_rx(skb);