input: make pnp device id constant

From: Márton Németh <[email protected]>

The id_table field of the struct pnp_driver is constant in <linux/pnp.h> so it is worth to make pnp_devids also constant.

The semantic match that finds this kind of pattern is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r@
disable decl_init,const_decl_init;
identifier I1, I2, x;
@@

	struct I1 {
	  ...
	  const struct I2 *x;
	  ...
	};

@s@
identifier r.I1, y;
identifier r.x, E;
@@

	struct I1 y = {
	  .x = E,
	};

@c@
identifier r.I2;
identifier s.E;
@@

	const struct I2 E[] = ... ;

@depends on !c@
identifier r.I2;
identifier s.E;
@@
+ const

	struct I2 E[] = ...;

// </smpl>

---

diff -u -p a/drivers/input/gameport/ns558.c b/drivers/input/gameport/ns558.c
@@ -166,7 +166,7 @@ static int ns558_isa_probe(int io)
 
 #ifdef CONFIG_PNP
 
-static struct pnp_device_id pnp_devids[] = {
+static const struct pnp_device_id pnp_devids[] = {
 	{ .id = "@P@0001", .driver_data = 0 }, /* ALS 100 */
 	{ .id = "@P@0020", .driver_data = 0 }, /* ALS 200 */
 	{ .id = "@P@1001", .driver_data = 0 }, /* ALS 100+ */