net/bnxt: validate RSS hash key length

net/bnxt: validate RSS hash key length

In bnxt_rss_hash_update_op, driver is proceeding with
bnxt_hwrm_vnic_rss_cfg even though RSS hashkey length is invalid.

This patch fixes the problem by returning -EINVAL when RSS hashkey
length is invalid.

Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Rahul Gupta <rahul.gupta@broadcom.com>
Reviewed-by: Santoshkumar Karanappa Rastapur <santosh.rastapur@broadcom.com>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>