Replace the last of the HAVE_EVENTFDs with HAVE_SYS_EVENTFD_H.

(cherry picked from commit b3d9ea87aa40d43f081b8fcecd7d0126e6865196)

src/misc/objects.c

@@ -391,7 +391,7 @@ int vlc_object_waitpipe( vlc_object_t *obj )
         /* This can only ever happen if someone killed us without locking: */
         assert (internals->pipes[1] == -1);
 
-#ifdef HAVE_EVENTFD
+#if defined (HAVE_SYS_EVENTFD_H)
         internals->pipes[0] = internals->pipes[1] = eventfd (0, 0);
         if (internals->pipes[0] == -1)
 #endif