release_vbscode doesn't do anything if ref is 0.

This typically happens when resizing a D3D child window.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54810

It is really useful to see at a glance what function is
segfaulting/crashing here when debugging games/apps.

This code is generated, and when generating WineVulkan against different
Vulkan spec versions, etc it may be misleading that the Line: referred
to by the assert dialog does not match what is generated locally on
a different machine for the same Wine version/commit.
Signed-off-by: Joshua Ashton <joshua@froggi.es>

To make it possible to support a larger structure.

Fixes a scan-build warning.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=51640

Similar to 35f9091b, IsRectEmpty() is the wrong way to check if padding is empty.