ALSA: ctxfi: constify rsc ops structures

The various rsc ops structures are never modified, so declare them as
const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/ctxfi/ctamixer.h b/sound/pci/ctxfi/ctamixer.h
index 72f42f2..2de18aa 100644
--- a/sound/pci/ctxfi/ctamixer.h
+++ b/sound/pci/ctxfi/ctamixer.h
@@ -58,7 +58,7 @@
 	unsigned char idx[8];
 	struct rsc *input;	/* pointer to a resource acting as source */
 	struct sum *sum;	/* Put amixer output to this summation node */
-	struct amixer_rsc_ops *ops;	/* AMixer specific operations */
+	const struct amixer_rsc_ops *ops;	/* AMixer specific operations */
 };
 
 struct amixer_rsc_ops {