emubd: fix MSVC compilation

[Mixaill]

fixes emubd compilation with pure MSVC compiler.

[geky]

Hi @Mixaill, thanks for the PR!

The emubd layer is actually changing significantly here:
#372

Though I'm not sure how #372 would effect MSVC.

[geky]

Thanks for the PR. But I'm going to go ahead and close this as the bd layer was rewritten in v2.2. It no longer calls mkdir, so I'm not sure what changes need to be made for MSVC support.