Description of problem:

When kdumpctl invokes dracut and there is a 'path' entry in /etc/kdump.conf, ,
the '--mount' argument that it uses will look like this:


   /sbin/dracut --quiet \
      --hostonly --hostonly-cmdline --hostonly-i18n --hostonly-mode strict \
      -o "plymouth dash resume ifcfg" \
      --mount "/dev/mapper/vg0/logs /kdumproot//logs ext4 defaults" \
      --no-hostonly-default-device \
      -f /boot/initramfs-4.14.0-1kdump.img 4.14.0-1

Intersting is that the '--mount' contains '/kdumproot//logs' (two slashes).

I was trying to pre-generate this initramfs on my own, but when doing
so, I provided it with a "cleaner" value for --mount:

    --mount "/dev/mapper/vg0/logs /kdumproot/logs ext4 defaults"


That triggers kdumpctl to "Detected change in File System"
as it compares 
   _new_mnt_point
to
   _old_mnt_point

_new_mnt_point gets set to:

    _new_mntpoint="/kdumproot/$(get_mntpoint_from_target $_target)"


So it is basically guaranteed to have a second '/'.


How reproducible:

Steps to Reproduce:
1. Remove kdump initramfs

   rm /boot/*-kdump

    dracut --no-hostonly -v -o "plymouth dash resume ifcfg" \
       --mount "/dev/mapper/vg0-logs /kdumproot/logs"
2. Set a value for path in /etc/kdump.conf:

    path /logs/crash

3. rm /boot/*kdump.img 
4. kdumpctl stop
5. kdumpctl start

You'll see that dracut is invoked with two / in the second argument to mount.

Additional info:

This isn't really all that big of a deal if kdumpctl is the only thing that is
going to generate an initramfs, but if anyone tries to do what I did, then
they're likely to hit the same issue.

The fix would be really just to clean the two paths for '_new_mntpoint' and
'_old_mntpoint' before comparing.