bug#37612: device-mapper: remove ioctl on cryptoroot failed: Device or resource busy

[theamazed74]

# Steps to reproduce:

I start going through the GUI installer and during the install I get these 
errors:

![memory-leak](https://coinsh.red/u/653Guix-Memory-Leak.jpeg) 
<https://coinsh.red/u/653Guix-Memory-Leak.jpeg>

Next I enter and get these:

![crypt-error]( 
<https://coinsh.red/u/Crypt-Error_647_.jpeg>https://coinsh.red/ipfs/QmWkYNpehzGZNeJquZb8ev39SzsQ9crmMfNofAnMKNdz4c
 <https://coinsh.red/ipfs/QmWkYNpehzGZNeJquZb8ev39SzsQ9crmMfNofAnMKNdz4c>) 
<https://coinsh.red/u/Crypt-Error_647_.jpeg>

Then after restarting I tried the first couple steps then it halted with these:

![bug(pg1)](https://coinsh.red/u/TheFirst566.jpeg) 
<https://coinsh.red/u/653Guix-Memory-Leak.jpeg>

![bug(pg2)]( 
<https://coinsh.red/u/653Guix-Memory-Leak.jpeg>https://coinsh.red/u/TheSECOND56677.jpeg
 <https://coinsh.red/u/TheSECOND566.jpeg>)

# What was expected?

I am not certain what these errors mean. I tried to RTFM but wasn't able to 
find much.