Fixed Cmake script for cases when VMA_STATIC_VULKAN_FUNCTIONS is not set

We need to statically link with Vulkan anyway, unless we use volk. VMA doesn't need it, but sample app does. Without this change, we had linker errors.

Author: adam-sawicki-a

src/CMakeLists.txt

@@ -56,8 +56,8 @@ target_sources(VmaSample PRIVATE
     ../include/vk_mem_alloc.h
 )
 
-# Only link to Vulkan library if static linking is used, but always add Vulkan headers directory
-if(VMA_STATIC_VULKAN_FUNCTIONS)
+# Only link to Vulkan library if volk loader is not used, but always add Vulkan headers directory.
+if("${VMA_VOLK_HEADER_PATH}" STREQUAL "")
     target_link_libraries(VmaSample PUBLIC Vulkan::Vulkan)
 else()
     target_link_libraries(VmaSample PUBLIC Vulkan::Headers)