ice: fix an error code in ice_ena_vfs()

Return the error code if ice_eswitch_configure() fails.  Don't return
success.

Fixes: 1c54c839 ("ice: enable/disable switchdev when managing VFs")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>