alsa-lib: pcm_plug: fix float conversion for user specified ttable
alsa-lib: pcm_plug: fix float conversion for user specified ttable

Move custom ttable with equal channels case from a separate ttable_last
exception into a common plugins insertion loop.
Fixes plug with ttable for float pcms (jack, ladspa).
Example: aplay -fFLOAT_LE /dev/zero
pcm.!default {
    type plug
    slave.pcm { type null }
    ttable.0.0 1
}

Signed-off-by: Sergey <d8b7478b40c8cd9913d07343728cccaae2528466@mail.ru>
Signed-off-by: Jaroslav Kysela <72edd5e1a572f82f059ccbb83c92b74d6cb051ff@perex.cz>

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