upstream: correct function name in debug message

OpenBSD-Commit-ID: 2482c99d2ce448f39282493050f8a01e3ffc39ab
diff --git a/sk-usbhid.c b/sk-usbhid.c
index c0a6bd0..f81dc8f 100644
--- a/sk-usbhid.c
+++ b/sk-usbhid.c
@@ -113,7 +113,7 @@
 	va_start(ap, fmt);
 	xvasprintf(&msg, fmt, ap);
 	va_end(ap);
-	debug("%s: %s", __func__, msg);
+	debug("%s: %s", func, msg);
 	free(msg);
 #elif defined(SK_DEBUG)
 	va_list ap;