Revert "Update to FreeBSD libm r336523."

This reverts commit f86ee10278116d211cfb08679416444e0e714cb5.

Incorrect result for fmodf(3.0f, 0f) = 1.0f breaks ART tests.

Bug: 111710419
Test: art/test/testrunner/testrunner.py -b -t 436-rem-float --target
Change-Id: I7eae68fb92740db33415d16418447bcbbd98ecba
diff --git a/libm/upstream-freebsd/lib/msun/ld128/s_expl.c b/libm/upstream-freebsd/lib/msun/ld128/s_expl.c
index 53bc04a..a6a9676 100644
--- a/libm/upstream-freebsd/lib/msun/ld128/s_expl.c
+++ b/libm/upstream-freebsd/lib/msun/ld128/s_expl.c
@@ -1,6 +1,4 @@
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
- *
  * Copyright (c) 2009-2013 Steven G. Kargl
  * All rights reserved.
  *
@@ -29,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/msun/ld128/s_expl.c 326219 2017-11-26 02:00:33Z pfg $");
+__FBSDID("$FreeBSD$");
 
 /*
  * ld128 version of s_expl.c.  See ../ld80/s_expl.c for most comments.