meson: use install_emptydir() and drop meson-make-symlink.sh

The script is mostly equivalent to 'mkdir -p' and 'ln -sfr'.
Let's replace it with install_emptydir() builtin function and
inline meson call.

src/kernel-install/meson.build

@@ -44,8 +44,7 @@ if want_kernel_install
                      install_dir : kerneldir)
 
         if install_sysconfdir
-                meson.add_install_script('sh', '-c',
-                                         mkdir_p.format(sysconfdir / 'kernel/install.d'))
+                install_emptydir(sysconfdir / 'kernel/install.d')
         endif
 endif