kodi-texturepacker: fix compilation error with host gcc 7.x

kodi-texturepacker: fix compilation error with host gcc 7.x

When host-kodi-texturepacker is built on a machine using gcc 7.x, it
fails to build with:

/usr/include/stdlib.h:443:14: error: declaration of ‘void* reallocarray(void*, size_t, size_t) throw ()’ has a different exception specifier
 extern void *reallocarray (void *__ptr, size_t __nmemb, size_t __size)

This commit backports the upstream fix for this problem.

The issue could be reproduced with the following defconfig (and a gcc
7.x host compiler):

BR2_x86_64=y
BR2_TOOLCHAIN_BUILDROOT_WCHAR=y
BR2_TOOLCHAIN_BUILDROOT_CXX=y
BR2_PACKAGE_KODI=y
BR2_PACKAGE_MESA3D=y
BR2_PACKAGE_MESA3D_GALLIUM_DRIVER_R600=y
BR2_PACKAGE_MESA3D_OPENGL_EGL=y
BR2_PACKAGE_XORG7=y
BR2_PACKAGE_PYTHON=y
BR2_PACKAGE_PYTHON_PY_PYC=y

Signed-off-by: Dagg Stompler <daggs@gmx.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>