tools/test: delete now returns a boolean

Updates the test mock expectation to return a boolean.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I8f10a1b561900295b2613317c09de688a4d9d944
diff --git a/tools/test/tools_updater_unittest.cpp b/tools/test/tools_updater_unittest.cpp
index 40b6798..51a2848 100644
--- a/tools/test/tools_updater_unittest.cpp
+++ b/tools/test/tools_updater_unittest.cpp
@@ -315,7 +315,7 @@
         .WillOnce(Return(true));
     EXPECT_CALL(handler, cleanArtifacts()).WillOnce(Return());
     EXPECT_CALL(blobMock, deleteBlob(ipmi_flash::activeImageBlobId))
-        .WillOnce(Return());
+        .WillOnce(Return(true));
     EXPECT_CALL(blobMock, getBlobList())
         .WillOnce(Return(std::vector<std::string>(
             {ipmi_flash::staticLayoutBlobId, ipmi_flash::activeImageBlobId})));