KVM test: kvm_tests: fix a litte bug in timedrift()

the original version compared a wrong drift value with given threshold.

Signed-off-by: Cao, Chen <kcao@redhat.com>

git-svn-id: http://test.kernel.org/svn/autotest/trunk@3622 592f7852-d20e-0410-864c-8624ca9c26a4
diff --git a/client/tests/kvm/kvm_tests.py b/client/tests/kvm/kvm_tests.py
index b100269..4e3391e 100644
--- a/client/tests/kvm/kvm_tests.py
+++ b/client/tests/kvm/kvm_tests.py
@@ -773,7 +773,7 @@
     # Fail the test if necessary
     if drift > drift_threshold:
         raise error.TestFail("Time drift too large: %.2f%%" % drift)
-    if drift > drift_threshold_after_rest:
+    if drift_total > drift_threshold_after_rest:
         raise error.TestFail("Time drift too large after rest period: %.2f%%"
                              % drift_total)