fix check for s_dv_preset function pointer to be NULL.
return -EINVAL if function pointer is NULL.
Signed-off-by: NLad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: NManjunath Hadli <manjunath.hadli@ti.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>