x11/libwacom: unbreak "make test"

[jbeich]

Test Plan

1. Add BUILD_DEPENDS+=${TEST_DEPENDS} to Makefile.local
2. Add pre-install: do-test to Makefile.local
3. Run poudriere testport x11/libwacom

(1) and (2) are workarounds for https://github.com/freebsd/poudriere/pull/355

[jbeich]

x11/libwacom/Makefile

23 ↗

(On Diff #69310)

Note1, upstream rejected POSIX shell in favor of readability. FreeBSD sh and other utilities are not pure POSIX anyway, so one can't expect other BSDs or GNU dash to have the same extensions.
Note2, any bash from PATH would do. bash -> zsh symlink works fine i.e., sometimes Zsh is faster Bash than GNU Bash. ;)

[imp]

What bashism is needed / used here?

[jbeich]

@imp, see https://github.com/linuxwacom/libwacom/commit/e2ea0f0d771f

[jbeich]

Ping. Making non-upstreamable changes is outside of scope for this review.