It was a silly thing to do in the film. In the book Harry repairs his wand with the elder wand not because he thinks it's too dangerous to have around but because it's not his wand it was Dumbledore's and it's legacy should have ended with him like he wanted, as it was buried with him in the white marble tomb. Harry repairs his wand because it was his original wand and more importantly it chose him back in Olivanders wand shop. Harry knows that his wand (Phoenix tail feather core from Fawks) will work better for him because of this.