sort-prop-types with callbacksLast returns the same error multiple times

[trygveaa]

When using the rule react/sort-prop-types with callbacksLast set to true, it sometimes returns the same error multiple times instead of showing different errors. For example with this code:

var Component = React.createClass({
  propTypes: {
    onChange: React.PropTypes.func,
    a: React.PropTypes.string,
    c: React.PropTypes.string,
    b: React.PropTypes.string,
  }
});

It gives this output:

  3:5  error  Callback prop types must be listed after all other prop types  react/sort-prop-types
  3:5  error  Callback prop types must be listed after all other prop types  react/sort-prop-types
  3:5  error  Callback prop types must be listed after all other prop types  react/sort-prop-types

The error for the position of onChange should only be printed once, and it should report that b or c is at the wrong position.