[PATCH] staging: greybus: hid: fix SET_REPORT return value

[Hao-Qun Huang <alvinhuang0603@gmail.com>]

__gb_hid_output_raw_report() stores the result of gb_hid_set_report()
in ret and even adjusts it to account for the report ID byte, but then
always returns 0.

This hides Greybus transport errors from HID_REQ_SET_REPORT callers,
and makes hidraw report zero bytes written to user space on success,
although hid_hw_raw_request() is expected to return the number of
bytes transferred or a negative errno. The sibling GET_REPORT path,
__gb_hid_get_raw_report(), already follows this convention.

Return ret like the other HID transport drivers do.

Fixes: 96eab779e198 ("greybus: hid: add HID class driver")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-fable-5
Signed-off-by: Hao-Qun Huang <alvinhuang0603@gmail.com>
---
diff --git a/drivers/staging/greybus/hid.c b/drivers/staging/greybus/hid.c
index f1f9f6fbc00e..1d7186eecd23 100644
--- a/drivers/staging/greybus/hid.c
+++ b/drivers/staging/greybus/hid.c
@@ -256,7 +256,7 @@ static int __gb_hid_output_raw_report(struct hid_device *hid, __u8 *buf,
 	if (report_id && ret >= 0)
 		ret++; /* add report_id to the number of transferred bytes */
 
-	return 0;
+	return ret;
 }
 
 static int gb_hid_raw_request(struct hid_device *hid, unsigned char reportnum,