Fix a typo to run the pbkdf crypto cipher tests on macOS.
$ make check-unit
...
87/102 qemu:unit / test-crypto-pbkdf OK 2.35s 17 subtests passed
Fixes: ebe0302ac8 ("tests/unit: build pbkdf test on macOS") Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>