[WIN32K] BSOD 0x7f when launching two shutdown in sequence

Thanks to whindsaks for the discovery

ReactOS 0.4.15-x86-dev (Build 20230709-0.4.15-dev-6289-g19c8574) (Commit 19c8574ec834acc8bc082fbe0dd62de73b22202e)

Reproduction steps:

1. Open command prompt
2. Launch the following command:

   shutdown /t 5 /r /f & shutdown /l

• Expected result: The user session should be logged off, then it should show the countdown dialog and shutdown the system in 5 seconds
• Actual result: Session disconnect, tries to draw the Shutdown timeout dialog but it will go soon with 0x7f bugcode.

Alternatively:

1. Use Win+R to start

   shutdown /t 60 /r /f

2. Perform "Logoff" from the Start menu
3. On the Ctrl+Alt+Del window try switching between it and the countdown window

Attaching debug log from DougLyons: cmd-shutdown-01.txt