fix installation of `modules.builtin.bin'

`modules.builtin.bin' is installed like a regular file, thereby ending
up in the wrong place when `--kmoddir' is in effect. Fix this by
specifying the installation destination.

modules.d/90kernel-modules/install

@@ -4,4 +4,4 @@
 [ -f /etc/modprobe.conf ] && dracut_install /etc/modprobe.conf
 dracut_install $(find /etc/modprobe.d/ -type f -name '*.conf')
 inst_hook cmdline 01 "$moddir/parse-kernel.sh"
-inst "$srcmods/modules.builtin.bin"
+inst "$srcmods/modules.builtin.bin" "/lib/modules/$kernel/modules.builtin.bin"