pmt: Improve libhelper and libpartition_map, etc.

srclib/libpartition_map/src/PartitionMap.cpp

@@ -136,7 +136,7 @@ basic_partition_map_builder::basic_partition_map_builder() {
     LOGN(MAP, ERROR) << "Cannot build map by any default search entry."
                      << std::endl;
 
-  LOGN(MAP, INFO) << "default constructor successfully ended work."
+  LOGN(MAP, INFO) << "default constructor ended work."
                   << std::endl;
   _insert_logicals(_build_map("/dev/block/mapper", true));
   _map_builded = true;

srclib/libpartition_map/src/Type.cpp

@@ -185,7 +185,7 @@ std::string basic_partition_map::find_(const std::string &name) const {
 size_t basic_partition_map::size() const { return _count; }
 
 bool basic_partition_map::empty() const {
-  return _count > 0;
+  return _count == 0;
 }
 
 void basic_partition_map::clear() {