s3:modules:vfs_virusfilter: Recent New_VFS changes break vfs_virusfilter_openat.

The_New_VFS introduces changes that broke vfs_virusfilter_openat. The assert to make sure certain checks would work broke, and may not be wise to keep anyway.

This patch fixes those breaks and converts to the SMB_VFS_FSTAT_NEXT instead of SMB_VFS_STAT_NEXT.

Checklist

• Commits have Signed-off-by: with name/author being identical to the commit author
• (optional, if backport required) Bugzilla bug filed and BUG: tag added
• Test suite updated with functionality tests
• Test suite updated with negative tests
• Documentation updated
• CI timeout is 3h or higher (see Settings/CICD/General pipelines/ Timeout)

This is not new functionality or changes to it, just keeping sync with VFS changes, hence no tests and no documentation. Let me know if and how to do tests if needed and I will start doing that.

Reviewer's checklist:

• There is a test suite reasonably covering new functionality or modifications
• Function naming, parameters, return values, types, etc., are consistent and according to README.Coding.md
• This feature/change has adequate documentation added
• No obvious mistakes in the code