Fixes SKIP_DIRECTX_SAMPLES to actually skip building directx9 and directx10 samples

Build/CMakeLists.txt

@@ -338,6 +338,8 @@ if(BUILD_SAMPLES)
     if(WIN32)
 		if(SKIP_DIRECTX_SAMPLES)
 			message("-- Skipping all DirectX samples")
+			set(SKIP_DIRECTX9_SAMPLE ON)
+			set(SKIP_DIRECTX10_SAMPLE ON)
 		else()
 			message("-- Determing if DirectX samples can be built")
 			include(FindDirectX)