perf env: Move perf_env out of header.h and session.c into separate object

Since it can be used separately from 'perf_session' and 'perf_header',
move it to separate include file and object, next csets will try to move
a perf_env__init() routine.

Tested-by: Wang Nan <wangnan0@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ff2rw99tsn670y1b6gxbwdsi@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 23fed17..728cb11 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -170,31 +170,13 @@
 	machine__delete_threads(&session->machines.host);
 }
 
-static void perf_session_env__exit(struct perf_env *env)
-{
-	zfree(&env->hostname);
-	zfree(&env->os_release);
-	zfree(&env->version);
-	zfree(&env->arch);
-	zfree(&env->cpu_desc);
-	zfree(&env->cpuid);
-
-	zfree(&env->cmdline);
-	zfree(&env->cmdline_argv);
-	zfree(&env->sibling_cores);
-	zfree(&env->sibling_threads);
-	zfree(&env->numa_nodes);
-	zfree(&env->pmu_mappings);
-	zfree(&env->cpu);
-}
-
 void perf_session__delete(struct perf_session *session)
 {
 	auxtrace__free(session);
 	auxtrace_index__free(&session->auxtrace_index);
 	perf_session__destroy_kernel_maps(session);
 	perf_session__delete_threads(session);
-	perf_session_env__exit(&session->header.env);
+	perf_env__exit(&session->header.env);
 	machines__exit(&session->machines);
 	if (session->file)
 		perf_data_file__close(session->file);