dracut --kmoddir fails on paths with traling /

[pvalena]

Describe the bug
There's an error in recently added commit 2c2bd86#diff-99bfb8fe311d6a59318f685a5e3401b59293b577968aa08cc4ff7320a163bb28R1034

The code added in the commit only works in interactive mode:

$ cat example.sh
set -x

drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug/
drivers_dir="${drivers_dir%%+(/)}"

Note the trailing / which the last line of the example.sh was supposed to remove:

$ bash example.sh
+ drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug/
+ drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug/

Only way I was able to trigger the correct behaviour was an interactive mode:

$ bash -i < example.sh
stty: 'standard input': Inappropriate ioctl for device
$ set -x
$
$ drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug/
+ drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug/
$ drivers_dir="${drivers_dir%%+(/)}"
+ drivers_dir=/root/test/tmp/lib/modules/6.2.0-63.fc39.x86_64+debug
$ exit

Distribution used
Fedora Rawhide

Dracut version
059

Init system
systemd

To Reproduce

Add trailing / to kmoddir:

$ dracut -f --kmoddir /lib/modules/`uname -r`/
dracut: drivers_dir path set via -k/--kmoddir must contain "/lib/modules/" as a parent of your kernel module directory,
dracut: or modules may not be placed in the correct location inside the initramfs.
dracut: was given: /lib/modules/6.1.12-200.fc37.x86_64/
dracut: expected: /lib/modules/6.1.12-200.fc37.x86_64/lib/modules/6.1.12-200.fc37.x86_64
dracut: Please move your modules into the correct directory structure and pass the new location,
dracut: or set DRACUT_KMODDIR_OVERRIDE=1 to ignore this check.

Expected behavior
Trailing / removed.

Additional context

[pvalena]

I have a simple fix - will submit PR now.