Sync upstream FreeBSD libm (trivial changes).

More interesting changes to come, but there's enough of this noise I'm
separating it out...

Test: treehugger
Change-Id: I0efc0ac860a147112369df7561ee48a92a2a5e84
diff --git a/libm/upstream-freebsd/lib/msun/ld128/k_expl.h b/libm/upstream-freebsd/lib/msun/ld128/k_expl.h
index 159338f..3faf7a7 100644
--- a/libm/upstream-freebsd/lib/msun/ld128/k_expl.h
+++ b/libm/upstream-freebsd/lib/msun/ld128/k_expl.h
@@ -1,7 +1,7 @@
 /* from: FreeBSD: head/lib/msun/ld128/s_expl.c 251345 2013-06-03 20:09:22Z kargl */
 
 /*-
- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2009-2013 Steven G. Kargl
  * All rights reserved.