test/cm_az_fs: cleanup data API usage
test/cm_az_fs: cleanup data API usage

elasto_data_free() no longer frees foreign buffers, so there's no need
to clear the buf pointer beforehand.

Signed-off-by: David Disseldorp <589a549dc9f982d9f46aeeb82a09ab6d87ccf1d8@suse.de>

ddiss/elasto,ddiss/elasto