cli: be more verbose about what GL api means on Linux/Mac
cli: be more verbose about what GL api means on Linux/Mac

Closes: https://github.com/apitrace/apitrace/issues/797

Signed-off-by: David Heidelberg <73adef92ca642da3fa7f170e944550efa21ff51a@collabora.com>

apitrace/apitrace,apitrace/apitrace,apitrace/apitrace,apitrace/apitrace