bnxt_en: Fix bnxt_hwrm_update_rss_hash_cfg()

We must specify the vnic id of the vnic in the input structure of this
firmware message.  Otherwise we will get an error from the firmware.

Fixes: 98a4322b ("bnxt_en: update RSS config using difference algorithm")
Reviewed-by: Kalesh Anakkur Purayil <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>