control: keep consistent usage of assertion
control: keep consistent usage of assertion

In most codes for control APIs, assertions are used to check given
arguments from applications. If the arguments are not expected, the
application is forced to abort. When NDEBUG is defined in the beginning
of the codes, no checks are performed.

Although, in snd_ctl_elem_set_bytes(), assertion is used with condition
statement. There's an intention to check the arguments regardless of
NDEBUG. However, this is not the same fashion in the codes.

This commit applies the same fashion to the function, to keep consistent
usage of assertion.

Signed-off-by: Takashi Sakamoto <d5ec7d0cd8074757a1f5eb708bc105c3065a65ea@sakamocchi.jp>
Signed-off-by: Takashi Iwai <4596b3305151c7ee743192a95d394341e3d3b644@suse.de>

takaswie/alsa-lib,takaswie/alsa-lib,alsa-project/alsa-lib,takaswie/alsa-lib,Distrotech/alsa-lib,zedongchen/alsa-lib,tiwai/alsa-lib,tiwai/alsa-lib,takaswie/alsa-lib,zedongchen/alsa-lib,Distrotech/alsa-lib,alsa-project/alsa-lib,alsa-project/alsa-lib,tiwai/alsa-lib,Distrotech/alsa-lib,alsa-project/alsa-lib,zedongchen/alsa-lib,Distrotech/alsa-lib,tiwai/alsa-lib,zedongchen/alsa-lib,takaswie/alsa-lib,zedongchen/alsa-lib,Distrotech/alsa-lib