message: Fix unused function warning
  Right now 'throw_on_error(hipError_t, char const*)' is not used,
  it will be used later and this warning will disappear.
diff: @@ -46,7 +46,7 @@ include(cmake/VerifyCompiler.cmake)
  set(CMAKE_CXX_STANDARD 11)
  set(CMAKE_CXX_STANDARD_REQUIRED ON)
  set(CMAKE_CXX_EXTENSIONS OFF)
  -set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror")
  +set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Werror -Wno-unused-function")
  # Build options
  option(BUILD_TEST "Build tests" ON)
  