ice: fix check for existing switch rule

ice: fix check for existing switch rule

In case the rule already exists and another VSI wants to subscribe to it
new VSI list is being created and both VSIs are moved to it.
Currently, the check for already existing VSI with the same rule is done
based on fdw_id.hw_vsi_id, which applies only to LOOKUP_RX flag.
Change it to vsi_handle. This is software VSI ID, but it can be applied
here, because vsi_map itself is also based on it.

Additionally change return status in case the VSI already exists in the
VSI map to "Already exists". Such case should be handled by the caller.

Signed-off-by: Mateusz Pacuszka <mateuszx.pacuszka@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>