[Bug] Restore-DbaDatabase backup size calc

[garethnewman]

Environmental information

#### PowerShell version:

Name                           Value                                                                                                                                                                                                                                
----                           -----                                                                                                                                                                                                                                
PSVersion                      5.1.14409.1018                                                                                                                                                                                                                                                                                                                                                                                                                                                  

#### dbatools Module version:
Name    : dbatools
Path    : C:\Program Files\WindowsPowerShell\Modules\dbatools\0.9.834\dbatools.psd1
Version : 0.9.834

#### SQL Server: 
Microsoft SQL Server 2016 (SP2-CU6)

#### Errors Received
NO ERRORS

#### Steps to Reproduce
Restore a database consisting of multiple files.

#### Expected Behavior
expect BackupSize to be the backup full size.

#### Actual Behavior
multiplying backup full size by backup file count, think it should divide it.

[potatoqualitee]

thanks gareth! any chance you can tackle this one? stuart has been out for a while.

[garethnewman]

Yes, I suspect there is an internal function being called as a quick CTRL+F didn't find what I was looking for. I'll sort it, should be simple enough once I find it.

[potatoqualitee]

thanks so much 🙇