don't error during newShader if a buffer is unused.

src/modules/graphics/Shader.cpp

@@ -1208,7 +1208,7 @@ bool Shader::validateInternal(StrongRef<ShaderStage> stages[], std::string &err,
 		{
 			const glslang::TQualifier &qualifiers = type->getQualifier();
 
-			if ((!qualifiers.isReadOnly() || qualifiers.isWriteOnly()) && (info.stages & EShLangComputeMask) == 0)
+			if ((!qualifiers.isReadOnly() || qualifiers.isWriteOnly()) && ((info.stages & (~EShLangComputeMask)) != 0))
 			{
 				err = "Shader validation error:\nStorage Buffer block '" + info.name + "' must be marked as readonly in vertex and pixel shaders.";
 				return false;