Sync libm with upstream FreeBSD.

Upstream SHA 78599c32efed3247d165302a1fbe8d9203e38974.

Test: treehugger
Change-Id: Ib103d211315e320df89a6f0bcb30cd8ba67dd603
diff --git a/libm/upstream-freebsd/lib/msun/src/e_fmod.c b/libm/upstream-freebsd/lib/msun/src/e_fmod.c
index fbb2d93..3a28dc4 100644
--- a/libm/upstream-freebsd/lib/msun/src/e_fmod.c
+++ b/libm/upstream-freebsd/lib/msun/src/e_fmod.c
@@ -12,7 +12,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/msun/src/e_fmod.c 336663 2018-07-24 10:10:16Z bde $");
+__FBSDID("$FreeBSD$");
 
 /* 
  * __ieee754_fmod(x,y)