[media] gspca - pac7302/pac7311: Fix some warnings

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/gspca/pac7302.c b/drivers/media/video/gspca/pac7302.c
index 55fbea7..2700975 100644
--- a/drivers/media/video/gspca/pac7302.c
+++ b/drivers/media/video/gspca/pac7302.c
@@ -393,7 +393,7 @@
 
 static void reg_w_buf(struct gspca_dev *gspca_dev,
 		  __u8 index,
-		  const char *buffer, int len)
+		  const u8 *buffer, int len)
 {
 	int ret;