Fix delta performer integration test.

Now we are saving signed context after every operation.

Bug: None
TEST=cros_workon_make update_engine --test

Change-Id: I5050c2caf83f2720a10c2d25b6542dbe823556fa
diff --git a/delta_performer_integration_test.cc b/delta_performer_integration_test.cc
index c483488..a14383c 100644
--- a/delta_performer_integration_test.cc
+++ b/delta_performer_integration_test.cc
@@ -700,9 +700,9 @@
       .WillRepeatedly(Return(true));
   EXPECT_CALL(prefs, SetString(kPrefsUpdateStateSHA256Context, _))
       .WillRepeatedly(Return(true));
+  EXPECT_CALL(prefs, SetString(kPrefsUpdateStateSignedSHA256Context, _))
+      .WillRepeatedly(Return(true));
   if (op_hash_test == kValidOperationData && signature_test != kSignatureNone) {
-    EXPECT_CALL(prefs, SetString(kPrefsUpdateStateSignedSHA256Context, _))
-        .WillOnce(Return(true));
     EXPECT_CALL(prefs, SetString(kPrefsUpdateStateSignatureBlob, _))
         .WillOnce(Return(true));
   }