Always use posix_memalign on OS X for consistency.  No functional change.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15636 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/tests/malloc.h b/tests/malloc.h
index 12afdf4..146790e 100644
--- a/tests/malloc.h
+++ b/tests/malloc.h
@@ -16,7 +16,7 @@
    void* x;
 #if defined(VGO_darwin)
    // Darwin lacks memalign, but its malloc is always 16-aligned anyway.
-   x = malloc(szB);
+   posix_memalign((void **)&x, 16, szB);
 #else
    x = memalign(16, szB);
 #endif