perf lock: Fix a memory leak on an error path

if a strdup-ed string is NULL,the allocated memory needs freeing.

Signed-off-by: zhaimingbing <[e-mail]>
Acked-by: Ingo Molnar <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Li Dong <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Sean Christopherson <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-lock.c

···
 		else
 			ev_name = strdup(contention_tracepoints[j].name);
 
-		if (!ev_name)
+		if (!ev_name) {
+			free(rec_argv);
 			return -ENOMEM;
+		}
 
 		rec_argv[i++] = "-e";
 		rec_argv[i++] = ev_name;