make-initrd.sh: Fix extracting initrd as non-root user

A non-root user cannot extract cpio archives that have read-only directories
with subdirectories or files unless these files appear in the archive
before the read-only directory.

The fix is to pass the -depth option to find, so that the contents of
directories get archived before the directories.
Merge branch 't/grsecurity' into t/all
Merge branch 't/initrd' into t/all
Merge branch 't/kernel-upd' into t/all
Merge branch 't/nixops-unstable' into t/all
Merge branch 't/vimrc' into t/all
Merge branch 't/xfs' into t/all
Revert "make-initrd.sh: Fix extracting initrd as non-root user"

This reverts commit 2b25ae11a22d4af0173040d5abbca5796c40b7f2.