nfp: flower: avoid newline at the end of message in NL_SET_ERR_MSG_MOD

Fix the following coccicheck warning:

    drivers/net/ethernet/netronome/nfp/flower/action.c:959:7-69: WARNING avoid newline at end of message in NL_SET_ERR_MSG_MOD

Signed-off-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220312095823.2425775-1-niklas.soderlund@corigine.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>