bnxt_en: avoid newline at end of message in NL_SET_ERR_MSG_MOD

Fix following coccicheck warning:
./drivers/net/ethernet/broadcom/bnxt/bnxt_devlink.c:446:8-56: WARNING
avoid newline at end of message in NL_SET_ERR_MSG_MOD.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Link: https://lore.kernel.org/r/20211102020312.16567-1-wanjiabing@vivo.com


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