Fix potential Longtail_GetFilesRecursively2 buffer overrun.

[webbju]

• Fix potential buffer overrun during Longtail_GetFilesRecursively2 when using a Job API.
  • The working buffer length calculation filters paths using IncludeFoundFile where as setup of job_contexts does not. This can lead to length inconsistencies. I managed to expose this by excluding certain directories via Regex (through golongtail CLI) which meant that LONGTAIL_FATAL_ASSERT(ctx, job_index == job_count, return ENOMEM); is hit when running golongtail with a debug static library (job_index > job_count). If not debug, exits with code 0xc0000374.