Sync upstream FreeBSD libm.

Test: treehugger
Change-Id: I583a3e93821d512c975db34fc1610ffd22445d58
diff --git a/libm/upstream-freebsd/lib/msun/src/e_expf.c b/libm/upstream-freebsd/lib/msun/src/e_expf.c
index 4903d55..620d341 100644
--- a/libm/upstream-freebsd/lib/msun/src/e_expf.c
+++ b/libm/upstream-freebsd/lib/msun/src/e_expf.c
@@ -43,7 +43,7 @@
 twom100 = 7.8886090522e-31;      /* 2**-100=0x0d800000 */
 
 float
-__ieee754_expf(float x)
+expf(float x)
 {
 	float y,hi=0.0,lo=0.0,c,t,twopk;
 	int32_t k=0,xsb;