Fix: static array larger than necessary

The longest string that can be returned should be 20 chars long, as per
the comment.

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: check malloc return value

Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: memory leak in lttng_enable_event_with_exclusions

lttng_enable_event_with_exclusions leaks a filter expression when
automatically generated filter statements are used. This happens when
loglevel and logger name filtering are used when enabling JUL events.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>
Fix: logger name dropped from filter condition when loglevels are used

This fix ensures that the loglevel expression is appended to the filter
expression and does not overwrite the current one.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Signed-off-by: David Goulet <dgoulet@efficios.com>