Bug 1668352

Description of problem:
In RHEL 8's multipath, a new option was introduced, 'alias_prefix', which allows to set the user_friendly_names prefix, by default "mpath". 
While playing with the new options for multipath, I found out that it was allowed to set up a multipath device that has the same name of an existing LV.
If you do this, and you try to reload or restart multipath, nothing happens other than complains from dmsetup because it cannot create the table, as expected. 
The problem comes if you add the prefix, rebuild the initramfs image with dracut, and then reboot - then you go into maintenance mode, and the only way to recover that I've found so far is to select the rescue initrd image in grub, or to copy and old image that doesn't contain multipathd (i.e. that wasn't created with "--add multipath".

Version-Release number of selected component (if applicable):
device-mapper-multipath-0.7.8-3.el8.

How reproducible:
Always

Steps to Reproduce:
1. Create a LV called /dev/test/testa
2. Set up 'alias_prefix' to be 'test-test'
3. Run 'multipath -v2 -ll'
4. At this point, multipath will fail to create the map (as expected) since there is already a table 'test-testa'.
5. Recreate initrd via dracut with "--add multipath"
6. Reboot

Actual results:
System will go into maintenance mode

Expected results:
System will boot normally. 

Additional info:
I'm attaching to this bz a rdsosreport.txt from the rescue environment. My next test will be booting with more debug and see if I capture more information.

To be honest I'm not sure if this is a multipath problem or a dracut problem. From multipath point of view we do prevent the map to exist, and if we never update dracut to include multipath, there is no issue at all.