[libgtop] Set the FSUSAGE_(READ|WRITE) flags only we managed to get something. Currently, it doesn't seem to w

[Robert Roth <robertroth src gnome org>]

commit c7f7e5a1c61cb47ccc777d5d77dd87c20f8a2a3a
Author: Benoit Dejean <bdejean gmail com>
Date:   Sat Feb 28 03:39:22 2015 +0100

    Set the FSUSAGE_(READ|WRITE) flags only we managed to get something. Currently, it doesn't seem to work 
on ZFS.

 sysdeps/freebsd/fsusage.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/sysdeps/freebsd/fsusage.c b/sysdeps/freebsd/fsusage.c
index 88b9b39..b6f87a0 100644
--- a/sysdeps/freebsd/fsusage.c
+++ b/sysdeps/freebsd/fsusage.c
@@ -132,7 +132,9 @@ _glibtop_get_fsusage_read_write (glibtop *server, glibtop_fsusage *buf, const ch
         buf->read = sfs.f_syncreads + sfs.f_asyncreads;
         buf->write = sfs.f_syncwrites + sfs.f_asyncwrites;
 #endif
-        buf->flags |= (1 << GLIBTOP_FSUSAGE_READ) | (1 << GLIBTOP_FSUSAGE_WRITE);
+       if (buf->read || buf->write) {
+                buf->flags |= (1 << GLIBTOP_FSUSAGE_READ) | (1 << GLIBTOP_FSUSAGE_WRITE);
+       }
 }
 
 void