(minor) Fix link issue in Release configuration

[Ybalrid]

The link library was called openxr instead of openxr_loader

[bradgrantham-lunarg]

This probably solves #29

[Ybalrid]

Hi,

This probably solves #29

Indeed, the linked post describes the same error I had, IIRC. CMake script using the wrong build target name to link the library. The CMake generator will assume this is a "system" library instead and will put a .lib prefix on it and say everything is fine.

Then the Visual Studio linker will error out because there is no openxr.lib file in any default linker path. But obviously, here we want to link against the Khronos OpenXR Loader library...🙂