dracut/99setup-root: Fix failed setup of wants dependency

The build log contained this error message:
  ln: failed to create symbolic link '/var/tmp/portage/sys-kernel/coreos-kernel-5.15.24/temp/dracut.Ddrb5k/initramfs//usr/lib/systemd/system/initrd.target.wants/initrd-setup-root.service': No such file or directory
Make sure the directory exists to be able to set up the link.

dracut/99setup-root/module-setup.sh

@@ -15,6 +15,7 @@ install() {
     inst_simple "${moddir}/initrd-setup-root.service" \
         "${systemdsystemunitdir}/initrd-setup-root.service"
 
+    mkdir -p "${systemdsystemunitdir}/initrd.target.wants"
     ln_r "${systemdsystemunitdir}/initrd-setup-root.service" \
         "${systemdsystemunitdir}/initrd.target.wants/initrd-setup-root.service"
 }