[UDFS] Fix driver load failure on Windows XP / POSReady 2009

[Copilot]

UDFS fails to load on Windows XP because KeAreAllApcsDisabled (introduced in WS03 SP1) is not exported by XP's ntoskrnl — the PE loader aborts before DriverEntry runs.

Changes

• misc.cpp: Replace KeAreAllApcsDisabled() with KeGetCurrentIrql() >= APC_LEVEL — the standard FS driver idiom, available on all NT versions.

• udfinit.cpp: Make FsRtlRegisterFileSystemFilterCallbacks failure non-fatal. Driver functions without the pre-acquire section synchronization callback.

• udffs.h: Zero POOL_NX_ALLOCATION (Win8+ flag, 0x200) in the __REACTOS__ compat block alongside existing NonPagedPoolNx/MdlMappingNoExecute downgrades. OR-ing it into lookaside list pool types produces an invalid type on XP-era kernels.

Original prompt

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This section details on the original issue you should resolve

<issue_title>[UDFS] It is having trouble loading under Windows XP</issue_title>
<issue_description>It is having trouble loading under Windows XP. I get the following error in Event Viewer:

The following boot-start or system-start driver(s) failed to load: 
Udfs
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes [UDFS] It is having trouble loading under Windows XP #61

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[Zero3K20]

@copilot Please fix the conflicts.

[Copilot]

@copilot Please fix the conflicts.

Fixed in 678dcd4. Merged udf-dev into the branch (resolving conflicts in cleanup.cpp, close.cpp, create.cpp, fileinfo.cpp, flush.cpp, misc.cpp, prefxsup.cpp, protos.h, strucsup.cpp, struct.h, udf_info.cpp, udf_info.h, udffs.h, and write.cpp by accepting the udf-dev version), then re-applied the three XP compatibility fixes on top.