net: ethtool: reject unsupported RSS input xfrm values

RXFH input_xfrm currently has three supported values: 0 (clear all),
symmetric_xor and NO_CHANGE.

Reject any other value sent from user-space.

Fixes: 13e59344 ("net: ethtool: add support for symmetric-xor RSS hash")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Ahmed Zaki <ahmed.zaki@intel.com>
Link: https://lore.kernel.org/r/20240104212653.394424-1-ahmed.zaki@intel.com


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