tests: replace BT_ASSERT with exit in test_bin_info

Since this is a test executable and not a library, it's cleaner to exit
with an error code than use an assertion which could be disabled.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Change-Id: I1684a21d510ea444106b84f5e06ece4a7ff96ef4
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1382
Tested-by: jenkins
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>
Reviewed-by: Francis Deslauriers <francis.deslauriers@efficios.com>