fix(lsinitrd): resolve initrd to real path

`lsinitrd /boot/initrd.img` fails in case the initrd is zstd compressed:

```
$ dracut --zstd --no-early-microcode --force
$ 3cpio --examine /boot/initrd.img
0	zstd
$ lsinitrd /boot/initrd.img
Image: /boot/initrd.img: 0
========================================================================
Warning : /boot/initrd.img is a symbolic link, ignoring
Version:

Arguments:
dracut modules:
Warning : /boot/initrd.img is a symbolic link, ignoring
Warning : /boot/initrd.img is a symbolic link, ignoring
========================================================================
========================================================================
cpio: premature end of archive

dracut cmdline:
Warning : /boot/initrd.img is a symbolic link, ignoring
```

The `CAT` variable is `zstd -d -c`. The zstd man page says about the
`--force` parameter: "disable input and output checks. Allows [...]
operating on links". So this zstd behavior is intentional.

Resolve the initrd path to the real path. Then `lsinitrd` prints the
correct content and image size:

```
$ lsinitrd /boot/initrd.img
Image: /boot/initrd.img-6.14.0-23-generic: 15M
[...]
```

Bug-Ubuntu: https://launchpad.net/bugs/2116183

diff --git a/lsinitrd.sh b/lsinitrd.sh
index ea26a260d5905aa6ec87cd1b408d34988f741283..688d659e96c21648e70c172e4424d219df3c01af 100755 (executable)
--- a/lsinitrd.sh
+++ b/lsinitrd.sh
@@ -173,6 +173,7 @@ if ! [[ -f $image ]]; then
     usage
     exit 1
 fi
+image=$(realpath "$image")
 
 TMPDIR="$(mktemp -d -t lsinitrd.XXXXXX)"
 # shellcheck disable=SC2064