rhn_check may lead to an OOM kill when used to install errata updates

Issue

• rhn_check may lead to an OOM kill when used to install errata updates
• rhn_check utilizes a lot of memory during errata updates when automatic updates are enabled
• This behaviour is not seen for new package installation. In this case too, memory usage is high, but not quite as high as errata updates.
• This happens when rhn_check is run from commandline as well as when it is run by rhnsd.
• Red Hat Network Satellite clients running out of memory.