iavf: fix inverted Rx hash condition leading to disabled hash

[ Upstream commit 32d57f667f871bc5a8babbe27ea4c5e668ee0ea8 ]

Condition, which checks whether the netdev has hashing enabled is
inverted. Basically, the tagged commit effectively disabled passing flow
hash from descriptor to skb, unless user *disables* it via Ethtool.
Commit a876c3ba ("i40e/i40evf: properly report Rx packet hash")
fixed this problem, but only for i40e.
Invert the condition now in iavf and unblock passing hash to skbs again.

Fixes: 857942fd ("i40e: Fix Rx hash reported to the stack by our driver")
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>