On SmartOS Facter tries to load an incompatible libsocket.so from a hardcoded path using ffi

Description of the bug: Facter tries to load an incompatible (32-bit) libsocket.so from a hardcoded path using ffi and fails to retrieve networking facts. Description of the fix: The library name is preferred instead of the hardcoded absolute path and networking facts can be retrieved on SmartOS. Contributed by smokris.