Input: turbografx - fix potential out of bound access

Patch 17dd3f0f7aa7: "[PATCH] drivers/input/joystick: convert to dynamic
input_dev allocation" from Sep 15, 2005, leads to the following static
checker warning:

drivers/input/joystick/turbografx.c:235 tgfx_probe()
error: buffer overflow 'tgfx_buttons' 5 <= 5

drivers/input/joystick/turbografx.c
195 for (i = 0; i < n_devs; i++) {
196 if (n_buttons[i] < 1)
197 continue;
198
199 if (n_buttons[i] > 6) {
^^^^^^^^^^^^^^^^
Possibly off by one. >= 6.

Let's change the upper value to ARRAY_SIZE(tgfx_buttons) to ensure we do
not reach past the end of the array.

Reported-by: Dan Carpenter <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/joystick/turbografx.c

···
 		if (n_buttons[i] < 1)
 			continue;
 
-		if (n_buttons[i] > 6) {
+		if (n_buttons[i] > ARRAY_SIZE(tgfx_buttons)) {
 			printk(KERN_ERR "turbografx.c: Invalid number of buttons %d\n", n_buttons[i]);
 			err = -EINVAL;
 			goto err_unreg_devs;