perf tools: Use zfree to help detect use after free bugs

Several areas already used this technique, so do some audit to
consistently use it elsewhere.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9sbere0kkplwe45ak6rk4a1f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index d3a857be..8ffe29c 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -132,18 +132,18 @@
 
 static void perf_session_env__delete(struct perf_session_env *env)
 {
-	free(env->hostname);
-	free(env->os_release);
-	free(env->version);
-	free(env->arch);
-	free(env->cpu_desc);
-	free(env->cpuid);
+	zfree(&env->hostname);
+	zfree(&env->os_release);
+	zfree(&env->version);
+	zfree(&env->arch);
+	zfree(&env->cpu_desc);
+	zfree(&env->cpuid);
 
-	free(env->cmdline);
-	free(env->sibling_cores);
-	free(env->sibling_threads);
-	free(env->numa_nodes);
-	free(env->pmu_mappings);
+	zfree(&env->cmdline);
+	zfree(&env->sibling_cores);
+	zfree(&env->sibling_threads);
+	zfree(&env->numa_nodes);
+	zfree(&env->pmu_mappings);
 }
 
 void perf_session__delete(struct perf_session *session)