V4L/DVB (8195): gspca: Input buffer overwritten in spca561 + cleanup code.

spca561:  Input buffer may be changed on reg write.
(all sd): Cleanup code, 'const' added.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index b369130..ad4721b 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -247,7 +247,7 @@
 struct gspca_frame *gspca_frame_add(struct gspca_dev *gspca_dev,
 				    int packet_type,
 				    struct gspca_frame *frame,
-				    __u8 *data,
+				    const __u8 *data,
 				    int len)
 {
 	int i, j;
@@ -1053,7 +1053,7 @@
 			 struct v4l2_control *ctrl)
 {
 	struct gspca_dev *gspca_dev = priv;
-	struct ctrl *ctrls;
+	const struct ctrl *ctrls;
 	int i, ret;
 
 	for (i = 0, ctrls = gspca_dev->sd_desc->ctrls;
@@ -1079,7 +1079,7 @@
 {
 	struct gspca_dev *gspca_dev = priv;
 
-	struct ctrl *ctrls;
+	const struct ctrl *ctrls;
 	int i, ret;
 
 	for (i = 0, ctrls = gspca_dev->sd_desc->ctrls;