Fix coding standards

@Pavan B S, Thanks for the patch, I checked your patch using coder module & it cures error & warnings which show in coder review, I attached the after & before result of the review.

The second "error" reported by Coder is actually a false positive because t() is considered safe in this case because the variable is just a conditional.

You could fix the false positive and avoid the unnecessary use of check_plain() by setting '#title' => t('Bundles'), then after the end of the array,

if ($target_type == 'node') {
  $form['settings']['entityreference_field']['target_bundles']['#title'] = t('Content types');
} 

Thanks! Committed to 7.x-1.x.