spi/of: Fix initialization of cs_gpios array

Using memset does not set an array of integers properly. Replace with a
loop to set each element properly.
Signed-off-by: NAndreas Larsson <andreas@gaisler.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/spi/spi.c

@@ -1080,7 +1080,8 @@ static int of_spi_register_master(struct spi_master *master)
 	if (!master->cs_gpios)
 		return -ENOMEM;
 
-	memset(cs, -EINVAL, master->num_chipselect);
+	for (i = 0; i < master->num_chipselect; i++)
+		cs[i] = -EINVAL;
 
 	for (i = 0; i < nb; i++)
 		cs[i] = of_get_named_gpio(np, "cs-gpios", i);