<form action="<?php echo OC_Helper::linkToRoute('core_lostpassword_reset', $_['args']) ?>" method="post">
	<fieldset>
		<?php if($_['success']): ?>
			<h1><?php echo $l->t('Your password was reset'); ?></h1>
			<p><a href="<?php echo OC_Helper::linkTo('', 'index.php') ?>/"><?php echo $l->t('To login page'); ?></a></p>
		<?php else: ?>
			<p class="infield">
				<label for="password" class="infield"><?php echo $l->t( 'New password' ); ?></label>
				<input type="password" name="password" id="password" value="" required />
			</p>
			<input type="submit" id="submit" value="<?php echo $l->t('Reset password'); ?>" />
		<?php endif; ?>
	</fieldset>
</form>

<form action="<?php print_unescaped(OC_Helper::linkToRoute('core_lostpassword_reset', $_['args'])) ?>" method="post">
	<fieldset>
		<?php if($_['success']): ?>
			<h1><?php p($l->t('Your password was reset')); ?></h1>
			<p><a href="<?php print_unescaped(OC_Helper::linkTo('', 'index.php')) ?>/"><?php p($l->t('To login page')); ?></a></p>
		<?php else: ?>
			<p class="infield">
				<label for="password" class="infield"><?php p($l->t('New password')); ?></label>
				<input type="password" name="password" id="password" value="" required />
			</p>
			<input type="submit" id="submit" value="<?php p($l->t('Reset password')); ?>" />
		<?php endif; ?>
	</fieldset>
</form>

Replace echo with `p` or `print_unescaped`
Replace echo with `p` or `print_unescaped`

Using echo instead of `p` or `print_unescaped` is a bad style, to prevent people from copying it  I've adjusted it.