flow_offload: fix flow_offload_has_one_action() kdoc

include/net/flow_offload.h:351: warning:
  No description found for return value of 'flow_offload_has_one_action'

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@amd.com>
Link: https://lore.kernel.org/r/20240410114718.15145-1-ast@fiberby.net


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