sata_sil24: Use const

Reduce data by using const.

$ size drivers/ata/sata_sil24.o*
   text	   data	    bss	    dec	    hex	filename
  12764	    614	   2688	  16066	   3ec2	drivers/ata/sata_sil24.o.new
  12320	   1058	   2688	  16066	   3ec2	drivers/ata/sata_sil24.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/sata_sil24.c

@@ -268,7 +268,7 @@ union sil24_cmd_block {
 	struct sil24_atapi_block atapi;
 };
 
-static struct sil24_cerr_info {
+static const struct sil24_cerr_info {
 	unsigned int err_mask, action;
 	const char *desc;
 } sil24_cerr_db[] = {
@@ -1019,7 +1019,7 @@ static void sil24_error_intr(struct ata_port *ap)
 
 	/* deal with command error */
 	if (irq_stat & PORT_IRQ_ERROR) {
-		struct sil24_cerr_info *ci = NULL;
+		const struct sil24_cerr_info *ci = NULL;
 		unsigned int err_mask = 0, action = 0;
 		u32 context, cerr;
 		int pmp;