HID: logitech-dj: Fix error handling in logi_dj_recv_switch_to_dj_mode()

Presently, if a call to logi_dj_recv_send_report() fails, we do
not learn about the error until after sending short
HID_OUTPUT_REPORT with hid_hw_raw_request().
To handle this somewhat unlikely issue, return on error in
logi_dj_recv_send_report() (minding ugly sleep workaround) and
take into account the result of hid_hw_raw_request().

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 6a9ddc8 ("HID: logitech-dj: enable notifications on connect/disconnect")
Signed-off-by: Nikita Zhandarovich <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Benjamin Tissoires <[email protected]>

Author: Nikita Zhandarovich

drivers/hid/hid-logitech-dj.c

@@ -1285,6 +1285,9 @@ static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
 		 * 50 msec should gives enough time to the receiver to be ready.
 		 */
 		msleep(50);
+
+		if (retval)
+			return retval;
 	}
 
 	/*
@@ -1306,7 +1309,7 @@ static int logi_dj_recv_switch_to_dj_mode(struct dj_receiver_dev *djrcv_dev,
 	buf[5] = 0x09;
 	buf[6] = 0x00;
 
-	hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
+	retval = hid_hw_raw_request(hdev, REPORT_ID_HIDPP_SHORT, buf,
 			HIDPP_REPORT_SHORT_LENGTH, HID_OUTPUT_REPORT,
 			HID_REQ_SET_REPORT);