staging: comedi: made comedi_lrange struct constant

Added the const type qualifier to the comedi_lrange structure.
Signed-off-by: Artur Lorincz <larturus@yahoo.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/addi_apci_3501.c

@@ -94,7 +94,7 @@ struct apci3501_private {
 	unsigned char timer_mode;
 };
 
-static struct comedi_lrange apci3501_ao_range = {
+static const struct comedi_lrange apci3501_ao_range = {
 	2, {
 		BIP_RANGE(10),
 		UNI_RANGE(10)