USB: Make file operations structs in drivers/usb const.

Making structs const prevents accidental bugs and with the proper debug
options they're protected against corruption.

Signed-off-by: Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/misc/idmouse.c b/drivers/usb/misc/idmouse.c
index fcd69c5..8e6e195 100644
--- a/drivers/usb/misc/idmouse.c
+++ b/drivers/usb/misc/idmouse.c
@@ -98,7 +98,7 @@
 static void idmouse_disconnect(struct usb_interface *interface);
 
 /* file operation pointers */
-static struct file_operations idmouse_fops = {
+static const struct file_operations idmouse_fops = {
 	.owner = THIS_MODULE,
 	.read = idmouse_read,
 	.open = idmouse_open,