ice: remove unused recipe bookkeeping data

Remove root_buf from recipe struct. Its only usage was in ice_find_recp(),
where if recipe had an inverse action, it was skipped, but actually the
driver never adds inverse actions, so effectively it was pointless.

Without root_buf, the recipe data element in ice_add_sw_recipe() does
not need to be persistent and can also be automatically deallocated with
__free, which nicely simplifies unroll.

Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>