Replace sprintf() by snprintf()

app/cdi.c

examples/pio/collectData.c

examples/pio/collectDataNStreams.c

src/cdf_write.c

src/iterator.c

src/iterator_fallback.c

src/iterator_grib.c

src/stream_cdf_i.c

src/stream_cdf_o.c

src/stream_cdf_time.c

src/stream_gribapi.c

src/table.c

src/util.c

src/vlist_var.c

tests/test_cdf_read.c