[gnome-system-monitor] Fix FTBFS on hurd

[Robert Roth <robertroth src gnome org>]

commit 786f497ab34e1d62d25b2242a9f27a2b8ebd934b
Author: Laurent Bigonville <l bigonville edpnet be>
Date:   Sun Feb 16 13:57:00 2014 +0000

    Fix FTBFS on hurd
    
    Author:    Laurent Bigonville <l bigonville edpnet be>
    
    https://bugzilla.gnome.org/show_bug.cgi?id=724482

 src/procproperties.cpp |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/src/procproperties.cpp b/src/procproperties.cpp
index 9c0f9ac..1627bf1 100644
--- a/src/procproperties.cpp
+++ b/src/procproperties.cpp
@@ -79,6 +79,12 @@ fill_proc_properties (GtkWidget *tree, ProcInfo *info)
     else
         HZ = (cinf.stathz ? cinf.stathz : cinf.hz);
 #endif
+#ifdef __GNU__
+    int HZ;
+    HZ = sysconf(_SC_CLK_TCK);
+    if (HZ < 0)
+        HZ = 100;
+#endif
     proc_arg proc_props[] = {
         { N_("Process Name"), g_strdup_printf("%s", info->name)},
         { N_("User"), g_strdup_printf("%s (%d)", info->user.c_str(), info->uid)},