Stocks End Up; Earnings, Merger Trump Oil  NEW YORK (Reuters) - U.S. stocks closed slightly higher on  Wednesday, as better-than-expected quarterly results from  investment bank Lehman Brothers Holdings Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=LEH.N target=/stocks/quickinfo/fullquote"&gt;LEH.N&lt;/A&gt; helped to  offset a two-week high in crude oil prices.