When a test program exits with a nonzero return value (or an assert is hit),
the test is regarded as a FAIL.
This makes `make check` a little more useful.
Passing a NULL-terminated array of pa_format_info pointers is a bit
unwieldy for clients. Instead of this, let's pass in an array of
pointers and the number of elements in the array.
This is just sync-playback.c modified to use the extended API. We need
something more sophisticated for properly testing the compressed
formats, but that is a non-trivial task in itself.
