Instead of doing sprintf twice in case the port is split or not, append
the split port suffix in case the port is split.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20210527104819.789840-1-jiri@resnulli.usSigned-off-by: Jakub Kicinski <kuba@kernel.org>