wsman-xml-serialize: use right sscanf parameters
wsman-xml-serialize: use right sscanf parameters

struct tm members are signed, so use %d instead of %u in sscanf

Signed-off-by: Alexander Usyskin <2c2d03d7dae842f113743879f565d486184f22a3@intel.com>

vcrhonek/openwsman,kkaempf/openwsman,Openwsman/openwsman,vcrhonek/openwsman,vcrhonek/openwsman,kkaempf/openwsman,kkaempf/openwsman,Openwsman/openwsman,Openwsman/openwsman,Openwsman/openwsman,kkaempf/openwsman,kkaempf/openwsman,Openwsman/openwsman,Openwsman/openwsman,kkaempf/openwsman,vcrhonek/openwsman,vcrhonek/openwsman,kkaempf/openwsman,vcrhonek/openwsman,Openwsman/openwsman,vcrhonek/openwsman