Fix build error for upgrading toolchain
'readdir_r' is deprecated since version 2.24 glibc.
By upgrading TOOLCHAIN for platform, it should be replaced by 'readdir'.
Different semantics for inline functions
While -std=gnu89 employs the GNU89 inline semantics, -std=gnu11 uses the
C99 inline semantics.
For further informaion, please refer to
'https://gcc.gnu.org/gcc-5/porting_to.html'
Remove unused function.
Change-Id: I0891770a16d91ee1fec75e3f2c1a48cc4c5fe6e3
Signed-off-by: Inkyun Kil <inkyun.kil@samsung.com>