[ALSA] au88x0: mem leak fix in snd_vortex_create()

In sound/pci/au88x0/au88x0.c::snd_vortex_create() :
The Coverity checker found that if we allocate storage for 'chip'
but then leave via the  regions_out:  label, then we end up leaking
the storage allocated for 'chip'.
I believe simply freeing 'chip' before the 'return err;' line is
all we need to fix this, but please double-check me :)

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>