all: don't include error->code in log messages

GError codes are only unique per domain, so logging the code without
also indicating the domain is not helpful. And anyway, if the error
messages are not distinctive enough to tell the whole story then we
should fix the error messages.

Based-on-patch-by: Dan Winship <danw@gnome.org>

src/nm-activation-request.c

@@ -303,8 +303,8 @@ nm_act_request_set_shared (NMActRequest *req, gboolean shared)
 			nm_log_info (LOGD_SHARING, "Executing: %s", cmd);
 			if (!g_spawn_sync ("/", argv, envp, G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL,
 			                   NULL, NULL, NULL, NULL, &status, &error)) {
-				nm_log_warn (LOGD_SHARING, "Error executing command: (%d) %s",
-				             error->code, error->message);
+				nm_log_warn (LOGD_SHARING, "Error executing command: %s",
+				             error->message);
 				g_clear_error (&error);
 			} else if (WEXITSTATUS (status)) {
 				nm_log_warn (LOGD_SHARING, "** Command returned exit status %d.",