The following line in linkedin.pages.inc approx line 74 in function linkedin_user_settings outputs text with no tag and no way to style it
$output .= t('You must first authorize LinkedIn integration to use related features.');

it could be easily moved to the function linkedin_user_enable_form as a #prefix form element as follows:
'#prefix' => '<p class="description">' . t('You must first authorize LinkedIn integration to use related features.') . '</p>',