HID: allow resizing and replacing report descriptors

Update hid_driver's report_fixup prototype to allow changing report
descriptor size and/or returning completely different report descriptor.
Update existing usage accordingly.

This is to give more freedom in descriptor fixup and to allow having a whole
fixed descriptor in the code for the sake of readability.

Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-cherry.c b/drivers/hid/hid-cherry.c
index 24663a8..e880086 100644
--- a/drivers/hid/hid-cherry.c
+++ b/drivers/hid/hid-cherry.c
@@ -26,15 +26,16 @@
  * Cherry Cymotion keyboard have an invalid HID report descriptor,
  * that needs fixing before we can parse it.
  */
-static void ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 17 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
+	if (*rsize >= 17 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
 		dev_info(&hdev->dev, "fixing up Cherry Cymotion report "
 				"descriptor\n");
 		rdesc[11] = rdesc[16] = 0xff;
 		rdesc[12] = rdesc[17] = 0x03;
 	}
+	return rdesc;
 }
 
 #define ch_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \