trace: [simple] Bump up log version number

The following tracetool cleanup changes the event numbering policy.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 8bbcb42..b9aeb56 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -65,13 +65,13 @@
        header[0] != header_event_id or \
        header[1] != header_magic:
         raise ValueError('Not a valid trace file!')
-    if header[2] != 0 and \
-       header[2] != 2:
-        raise ValueError('Unknown version of tracelog format!')
 
     log_version = header[2]
-    if log_version == 0:
-        raise ValueError('Older log format, not supported with this QEMU release!')
+    if log_version not in [0, 2, 3]:
+        raise ValueError('Unknown version of tracelog format!')
+    if log_version != 3:
+        raise ValueError('Log format %d not supported with this QEMU release!'
+                         % log_version)
 
     while True:
         rec = read_record(edict, fobj)