spi: offload: remove unnecessary check on trigger->ops

spi: offload: remove unnecessary check on trigger->ops

Considering that trigger->ops = NULL happens only when the trigger is
being removed from the list, and at that point the operation is protected
with the spi_offload_triggers_lock, it is possible to remove the
!trigger->ops check because it will never be true in
spi_offload_trigger_get()

Signed-off-by: Andres Urian Florez <andres.emb.sys@gmail.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250418171426.9868-1-andres.emb.sys@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>