Sometimes pkg-config says /lib/udev, qlist says /lib64/udev

At least on my systems I see the following discrepancy, which prevents
these udev rules from getting copied onto the initramfs.

    > pkg-config --variable udevdir udev
    /lib/udev

    > qlist -e sys-fs/lvm2:0 | grep -F /rules.d/
    /lib64/udev/rules.d/11-dm-lvm.rules
    /lib64/udev/rules.d/69-dm-lvm-metad.rules
    /lib64/udev/rules.d/10-dm.rules
    /lib64/udev/rules.d/13-dm-disk.rules
    /lib64/udev/rules.d/95-dm-notify.rules

Using "realpath" to standardize these paths.