spdlog dependency shouldn't need to be exported

[sloretz]

rcl_logging/rcl_logging_spdlog/CMakeLists.txt

Line 64 in e2456ba

ament_export_dependencies(ament_cmake rcl_logging_interface rcutils spdlog_vendor spdlog)

If I understand correctly there's no reason to ament_export_dependencies(spdlog spdlog_vendor). This call makes downstream packages find_package() them, but downstream code shouldn't need to know about them at all in order to use this logging implementation. The <exec_depend>spdlog* is enough to make the spdlog libraries available at runtime.

@hidmic thoughts?

[sloretz]

IIUC rcutils and rcl_logging_interface don't need to be "exported" either.

[sloretz]

I think the ament_cmake export happens automatically too, it seems like the whole line could be deleted

[hidmic]

Agree with this. And the same applies to log4cxx in rcl_logging_log4cxx.