xvcu_remove() is only called for a device after after xvcu_probe()
completed successfully. In that case dev_set_drvdata() was called for
that device with a non-NULL parameter, so platform_get_drvdata() won't
return NULL and the if condition is never true.

Drop the if, preparing a conversion to make platform driver's remove
callback return void.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230312161512.2715500-4-u.kleine-koenig@pengutronix.deSigned-off-by: Stephen Boyd <sboyd@kernel.org>