Makefile: drop usage of 'which'

[thesamesam]

which is an external command which isn't required by POSIX.

Debian and other distributions (like Gentoo!) are looking to drop it from their base set of packages.

Switch to command -v which should always work instead.

Signed-off-by: Sam James sam@gentoo.org

[orudge]

In terms of code changes, this seems fine. Could you amend the commit title to meet with the commit checker requirements please? (e.g. "Change: Drop usage of 'which' in Makefile")

[thesamesam]

Done and thank you.

[thesamesam]

Thanks!