Comment # 8 on bug 1037021 from Takashi Iwai

Thanks for testing, and sorry, this was the wrong information.  There is no
override of the config directory by the environment variable. 
$ALSA_CONFIG_PATH specifies the main config file, but it can't change the
default config path that other files may include.

After thinking of this problem and the current situation again, I concluded
that removing the new stuff would be better so that the old alsa-lib can still
work somehow.  Although the usage of the old alsa-lib with the new config is
clearly invalid, your use case implies that it's widely deployed, and we should
avoid breakage.

I'll fix up the upstream code and backport.