phosphor-ipmi-flash: Fix all C++ warnings

Change-Id: I89236b2dab88ca725e269bb8f5b2cbfd271e807a
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/tools/test/tools_lpc_unittest.cpp b/tools/test/tools_lpc_unittest.cpp
index 7699609..b180df5 100644
--- a/tools/test/tools_lpc_unittest.cpp
+++ b/tools/test/tools_lpc_unittest.cpp
@@ -62,7 +62,7 @@
         .WillOnce(Return(0));
 
     EXPECT_CALL(ioMock, write(_, data.size(), _))
-        .WillOnce(Invoke([&data](const std::size_t, const std::size_t length,
+        .WillOnce(Invoke([&data](const std::size_t, const std::size_t,
                                  const void* const source) {
             EXPECT_THAT(std::memcmp(source, data.data(), data.size()), 0);
             return true;