fixed 2 possible heap overflows (inc. #1088)
void hinf_del(GF_Box *s)
{
	GF_HintInfoBox *hinf = (GF_HintInfoBox *)s;
	gf_free(hinf);
}

void hinf_del(GF_Box *s)
{
	GF_HintInfoBox *hinf = (GF_HintInfoBox *)s;
	gf_free(hinf);
}
