Move the lockdep asserts until after the ctl pointer has been checked
for NULL, to avoid potentially NULL pointer dereferences.

Fixes: fb2f364fb5b9 ("firmware: cs_dsp: Add lockdep asserts to interface functions")
Reported-by: Nkernel test robot <lkp@intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20211130102842.26410-1-ckeepax@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>