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/src/e_fmodf.c b/libm/upstream-freebsd/lib/msun/src/e_fmodf.c
index 5a103f2..52ce373 100644
--- a/libm/upstream-freebsd/lib/msun/src/e_fmodf.c
+++ b/libm/upstream-freebsd/lib/msun/src/e_fmodf.c
@@ -14,7 +14,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/msun/src/e_fmodf.c 336362 2018-07-17 07:42:14Z bde $");
+__FBSDID("$FreeBSD$");
 
 /*
  * __ieee754_fmodf(x,y)
@@ -41,7 +41,7 @@
     /* purge off exception values */
 	if(hy==0||(hx>=0x7f800000)||		/* y=0,or x not finite */
 	   (hy>0x7f800000))			/* or y is NaN */
-	    return nan_mix(x, y)/nan_mix(x, y);
+	    return (x*y)/(x*y);
 	if(hx<hy) return x;			/* |x|<|y| return x */
 	if(hx==hy)
 	    return Zero[(u_int32_t)sx>>31];	/* |x|=|y| return x*0*/