Small fixes in functions generating Smack labels
Small fixes in functions generating Smack labels

- properly release memory in SmackLabels::getSmackLabelFromSocket()
- use libsmack function in SmackLabels::getSmackLabelFromPath()

Change-Id: I837947a16dff90d84e751176cab0692cd70278c0

Samsung/security-manager,Samsung/security-manager,Samsung/security-manager