libtracefs: Avoid null access

The for loop handles devents == NULL, but the test afterwards needs to
also.

Link: https://lore.kernel.org/linux-trace-devel/20220224234823.1190425-2-irogers@google.com

Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
1 file changed