Intel Clouded by Back-To-School Fears  SAN FRANCISCO (Reuters) - Intel Corp.'s &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=INTC.O target=/stocks/quickinfo/fullquote"&gt;INTC.O&lt;/A&gt; upcoming  mid-quarter report will be closely watched for signs of weak  back-to-school computer sales, though recent market share gains  in memory chips could help offset any softness in computer  microprocessor demand.