Replace local MUSL define with global ANDROID_HOST_MUSL

Bug: 190084016
Test: m USE_HOST_MUSL=true bionic-unit-tests-glibc
Change-Id: I56b23576cb24912112d2ae56d8ecc2e3716982fe
diff --git a/tests/fenv_test.cpp b/tests/fenv_test.cpp
index ea3f539..c5b5eca 100644
--- a/tests/fenv_test.cpp
+++ b/tests/fenv_test.cpp
@@ -20,6 +20,7 @@
 
 #include <fenv.h>
 #include <stdint.h>
+#include <sys/cdefs.h>
 
 static void TestRounding(float expectation1, float expectation2) {
   // Volatile to prevent compile-time evaluation.
@@ -170,7 +171,7 @@
 }
 
 TEST(fenv, fedisableexcept_fegetexcept) {
-#if !defined(MUSL)
+#if !defined(ANDROID_HOST_MUSL)
   feclearexcept(FE_ALL_EXCEPT);
   ASSERT_EQ(0, fetestexcept(FE_ALL_EXCEPT));
 
@@ -185,7 +186,7 @@
 }
 
 TEST(fenv, feenableexcept_fegetexcept) {
-#if !defined(MUSL)
+#if !defined(ANDROID_HOST_MUSL)
 #if defined(__aarch64__) || defined(__arm__)
   // ARM doesn't support this. They used to if you go back far enough, but it was removed in
   // the Cortex-A8 between r3p1 and r3p2.