Avoid double free by making trace_instance_destroy indempotent.  When
trace_instance_init fails, it calls trace_instance_destroy, but its only
caller osnoise_destroy_tool calls it again.
Link: https://lkml.kernel.org/r/mvmilnlkyzx.fsf_-_@suse.de
Fixes: 0605bf009f18 ("rtla: Add osnoise tool")
Signed-off-by: Andreas Schwab <schwab@suse.de>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
 
        if (trace->inst) {
                disable_tracer(trace->inst);
                destroy_instance(trace->inst);
+               trace->inst = NULL;
        }
 
-       if (trace->seq)
+       if (trace->seq) {
                free(trace->seq);
+               trace->seq = NULL;
+       }
 
-       if (trace->tep)
+       if (trace->tep) {
                tep_free(trace->tep);
+               trace->tep = NULL;
+       }
 }
 
 /*