fixup! f7c4383 docs update

Author: tgross35

libm/src/math/support/feature_detect.rs

@@ -64,8 +64,8 @@ macro_rules! select_once {
 
         let raw: *mut () = FUNC.load(Ordering::Relaxed);
 
-        // SAFETY: will only ever be `initializer`, or a reference that was stored with
-        // the 'static lifetime.
+        // SAFETY: will only ever be `initializer` or another function pointer that has the
+        // 'static lifetime.
         let fn_ptr: Func = unsafe { mem::transmute::<*mut (), Func>(raw) };
 
         $call(fn_ptr)