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/usblcd.c b/drivers/usb/misc/usblcd.c
index e095772..53e59e3 100644
--- a/drivers/usb/misc/usblcd.c
+++ b/drivers/usb/misc/usblcd.c
@@ -239,7 +239,7 @@
 	return retval;
 }
 
-static struct file_operations lcd_fops = {
+static const struct file_operations lcd_fops = {
         .owner =        THIS_MODULE,
         .read =         lcd_read,
         .write =        lcd_write,