sink.text.pretty: don't use printf for binary values

sink.text.pretty: don't use printf for binary values

printf is slow compared to simply appending '1' or '0' characters to the
GString.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I2605c1e6d2dc463be237e8eb00f70a84e4c5fd1a
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1507
CI-Build: Philippe Proulx <eeppeliteloop@gmail.com>
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Reviewed-by: Francis Deslauriers <francis.deslauriers@efficios.com>