alsactl: add define to compile with glibc 2.38

alsa-project/alsa-utils pull request #225 was opened from heitbaum:

strlcat and strlcpy have been added to glibc 2.38. update the defines to use the glibc versions, and not conflict with string.h.

ref: - https://sourceware.org/git/?p=glibc.git;a=commit;h=454a20c8756c9c1d554191532...

Request URL : https://github.com/alsa-project/alsa-utils/pull/225 Patch URL : https://github.com/alsa-project/alsa-utils/pull/225.patch Repository URL: https://github.com/alsa-project/alsa-utils