Kernel - Correct Code Analysis warnings

[Liryna]

Since https://github.com/dokan-dev/dokany/issues/837, warnings are provided at debug build time. This issue is to track the progress on fix / ignore those warnings.

[Karandra]

I'm not sure whether I should create a new issues for this or not, this place seems fine. I ran the PVS-Studio static analyzer on both v1.3 and v2.0 branches. Here are the reports, maybe you could find them useful.

v1.3.zip v2.0.zip