tools/kvm_stat: add line for totals

Add a line for the total number of events and current average at the
bottom of the body.
Note that both values exclude child trace events. I.e. if drilldown is
activated via interactive command 'x', only the totals are accounted, or
we'd be counting these twice (see previous commit "tools/kvm_stat: fix
child trace events accounting").
Signed-off-by: NStefan Raspl <raspl@linux.vnet.ibm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

tools/kvm/kvm_stat/kvm_stat

@@ -1099,8 +1099,9 @@ class Tui(object):
             sortkey = sortCurAvg
         else:
             sortkey = sortTotal
+        tavg = 0
         for key in sorted(stats.keys(), key=sortkey):
-            if row >= self.screen.getmaxyx()[0]:
+            if row >= self.screen.getmaxyx()[0] - 1:
                 break
             values = stats[key]
             if not values[0] and not values[1]:
@@ -1112,9 +1113,15 @@ class Tui(object):
                 self.screen.addstr(row, 1, '%-40s %10d%7.1f %8s' %
                                    (key, values[0], values[0] * 100 / total,
                                     cur))
+                if cur is not '' and key.find('(') is -1:
+                    tavg += cur
             row += 1
         if row == 3:
             self.screen.addstr(4, 1, 'No matching events reported yet')
+        else:
+            self.screen.addstr(row, 1, '%-40s %10d        %8s' %
+                               ('Total', total, tavg if tavg else ''),
+                               curses.A_BOLD)
         self.screen.refresh()
 
     def show_msg(self, text):