libtraceevent: Improve error handling of tep_plugin_add_option() API

In case of memory error, ensure all allocated resources are freed.
Do not append broken option in trace_plugin_options list.

Link: https://lore.kernel.org/r/CAM9d7cizjF+fbK7YzmsBDgrx__4YAOsmEq67D3sWET8FF+YdFA@mail.gmail.com
Link: https://lore.kernel.org/linux-trace-devel/20200714103027.2477584-5-tz.stoyanov@gmail.com

Suggested-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
1 file changed