Fix build error

Fix build error

[   39s] /usr/lib/gcc/armv7l-tizen-linux-gnueabi/9.2.0/include/c++/bits/stl_map.h: In member function 'int LowmemLimitEnv::
cgroup_make_subdir(const char*, const char*, bool*)':
[   39s] /usr/lib/gcc/armv7l-tizen-linux-gnueabi/9.2.0/include/c++/bits/stl_map.h:499:8: note: parameter passing for argument of
type 'std::_Rb_tree<std::__cxx11::basic_string<char>, std::pair<const std::__cxx11::basic_string<char>, LowmemLimitEnv::CGroupData>
, std::_Select1st<std::pair<const std::__cxx11::basic_string<char>, LowmemLimitEnv::CGroupData> >, std::less<std::__cxx11::basic_
string<char> >, std::allocator<std::pair<const std::__cxx11::basic_string<char>, LowmemLimitEnv::CGroupData> > >::const_iterator'
{aka 'std::_Rb_tree_const_iterator<std::pair<const std::__cxx11::basic_string<char>, LowmemLimitEnv::CGroupData> >'} changed in GCC 7.1

Change-Id: Ia62b225a8d26983eced992f7dac5d6b625254487
Signed-off-by: Hyotaek Shim <hyotaek.shim@samsung.com>