Fix arm64 build (#303)

The cmake module was located in another folder.

Author: Rayman

openvdb_vendor/CMakeLists.txt

@@ -5,6 +5,7 @@ find_package(ament_cmake REQUIRED)
 find_package(ament_cmake_vendor_package REQUIRED)
 
 list(APPEND CMAKE_MODULE_PATH "/usr/lib/x86_64-linux-gnu/cmake/OpenVDB")
+list(APPEND CMAKE_MODULE_PATH "/usr/lib/aarch64-linux-gnu/cmake/OpenVDB")
 find_package(OpenVDB 10 QUIET)
 
 ament_vendor(${PROJECT_NAME}