Fix alsa-utils building error on NetBSD

[GitHub pull_request - opened]

alsa-project/alsa-lib pull request #169 was opened from triaxx:

The following errors occur at least on NetBSD 9.2 amd64 when building
alsa-utils:
include/alsa/output.h:75:66: error: unknown type name 'va_list'; did you mean '__va_list'?
include/alsa/error.h:80:25: error: unknown type name 'va_list'; did you mean '__va_list'?

Request URL   : https://github.com/alsa-project/alsa-lib/pull/169
Patch URL     : https://github.com/alsa-project/alsa-lib/pull/169.patch
Repository URL: https://github.com/alsa-project/alsa-lib