Sysco Profit Rises; Sales Volume Flat  CHICAGO (Reuters) - Sysco Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=SYY.N target=/stocks/quickinfo/fullquote"&gt;SYY.N&lt;/A&gt;, the largest U.S.  distributor of food to restaurants and hospitals, on Monday  said quarterly profit rose as an extra week in the period and  cost control measures helped offset the higher food prices that  were slowing demand.