firmware: arm_scmi: Add delayed response status check

A successfully received delayed response could anyway report a failure at
the protocol layer in the message status field.

Add a check also for this error condition.

Link: https://lore.kernel.org/r/20210608103056.3388-1-cristian.marussi@arm.com
Fixes: 58ecdf03 ("firmware: arm_scmi: Add support for asynchronous commands and delayed response")
Signed-off-by: NCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>

drivers/firmware/arm_scmi/driver.c

@@ -517,8 +517,12 @@ static int do_xfer_with_response(const struct scmi_protocol_handle *ph,
 	xfer->async_done = &async_response;
 
 	ret = do_xfer(ph, xfer);
-	if (!ret && !wait_for_completion_timeout(xfer->async_done, timeout))
-		ret = -ETIMEDOUT;
+	if (!ret) {
+		if (!wait_for_completion_timeout(xfer->async_done, timeout))
+			ret = -ETIMEDOUT;
+		else if (xfer->hdr.status)
+			ret = scmi_to_linux_errno(xfer->hdr.status);
+	}
 
 	xfer->async_done = NULL;
 	return ret;