`CommandBufferKhr::finalizeCommandBuffer()` causes link failure

[jansol]

Looks like its trying to invoke the function as ::clFinalizeCommandBufferKHR, but since that is an extension fn it is not found by the build time linker when linking against an ICD loader.

Given that the other member functions in the CommandBufferKhr class appear to be using symbols like pfn_clCreateCommandBufferKHR which are fetched via clGetExtensionFunctionAddressForPlatform, this looks like a trivial oversight.