[PATCH 1/4] perf cgroup: Avoid needless closing of unopened fd

[Tommi Rantala <tommi.t.rantala@nokia.com>]

Do not bother with close() if fd is not valid, just to silence valgrind:

    $ valgrind ./perf script
    ==59169== Memcheck, a memory error detector
    ==59169== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
    ==59169== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
    ==59169== Command: ./perf script
    ==59169==
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()
    ==59169== Warning: invalid file descriptor -1 in syscall close()

Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
---
 tools/perf/util/cgroup.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c
index b73fb7823048..050dea9f1e88 100644
--- a/tools/perf/util/cgroup.c
+++ b/tools/perf/util/cgroup.c
@@ -107,7 +107,8 @@ static int add_cgroup(struct evlist *evlist, const char *str)
 
 static void cgroup__delete(struct cgroup *cgroup)
 {
-	close(cgroup->fd);
+	if (cgroup->fd >= 0)
+		close(cgroup->fd);
 	zfree(&cgroup->name);
 	free(cgroup);
 }
-- 
2.25.2