logind: actually close fd in launcher_logind_close

We still need to close fds passed to us - or we leak quite a few fds
on VC switch.

Regression, originally fixed in 8f5acc2f3a29c3831af4ddd6bed57f703c98dc77
and re-broken in commit 72dea06d7952e3ce8dd8057f7106186da4fa2678
but only for the logind launcher.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/libweston/launcher-logind.c b/libweston/launcher-logind.c
index f10a283..a069bd4 100644
--- a/libweston/launcher-logind.c
+++ b/libweston/launcher-logind.c
@@ -216,6 +216,7 @@
 	int r;
 
 	r = fstat(fd, &st);
+	close(fd);
 	if (r < 0) {
 		weston_log("logind: cannot fstat fd: %m\n");
 		return;