Fix token serial number matching when trying to find hidden PKCS#11 key
Fix token serial number matching when trying to find hidden PKCS#11 key

Spotted by Coverity.

Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

lins05/openconnect,chadcatlett/openconnect,lins05/openconnect,mtmiller/openconnect,nmav/openconnect-mine,cernekee/openconnect,don-johnny/openconnect,matlockx/openconnect,atyndall/openconnect,neshema/openconnect,mtmiller/openconnect,liiir1985/openconnect,mtmiller/openconnect,neshema/openconnect,cernekee/openconnect,don-johnny/openconnect,nmav/openconnect-mine,matlockx/openconnect,atyndall/openconnect,don-johnny/openconnect,cernekee/openconnect,neshema/openconnect,nmav/openconnect-mine,brandt/openconnect,mveplus/openconnect-client,matlockx/openconnect,cernekee/openconnect,mveplus/openconnect-client,liiir1985/openconnect,mveplus/openconnect-client,matlockx/openconnect,atyndall/openconnect,mveplus/openconnect-client,brandt/openconnect,chadcatlett/openconnect,atyndall/openconnect,brandt/openconnect,liiir1985/openconnect,chadcatlett/openconnect,mtmiller/openconnect,lins05/openconnect,don-johnny/openconnect,lins05/openconnect,chadcatlett/openconnect,brandt/openconnect,liiir1985/openconnect,neshema/openconnect,nmav/openconnect-mine