test: fixup boost endian change

handler_unittest.cpp:172:57: error: no matching function call...
The issue is that endian data() changed output to unsigned char* which
is not supported by the std::string constructor.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I7008490bff085f5eb0b81c03b27937c146ecb672
diff --git a/test/handler_unittest.cpp b/test/handler_unittest.cpp
index b6d204e..217b1d6 100644
--- a/test/handler_unittest.cpp
+++ b/test/handler_unittest.cpp
@@ -169,7 +169,8 @@
     // Serialize to string stored in the fakeSysFile
     auto staleBlobData = staleBlob.SerializeAsString();
     boost::endian::little_uint64_t sizeLE = staleBlobData.size();
-    std::string commitData(sizeLE.data(), sizeof(sizeLE));
+    std::string commitData(reinterpret_cast<const char*>(sizeLE.data()),
+                           sizeof(sizeLE));
     commitData += staleBlobData;
 
     std::vector<std::string> expectedIdList = {basicTestBaseId};
@@ -191,7 +192,8 @@
 TEST_F(BinaryStoreBlobHandlerBasicTest, CreatingFromJunkData)
 {
     boost::endian::little_uint64_t tooLarge = 0xffffffffffffffffull;
-    const std::string junkDataWithLargeSize(tooLarge.data(), sizeof(tooLarge));
+    const std::string junkDataWithLargeSize(
+        reinterpret_cast<const char*>(tooLarge.data()), sizeof(tooLarge));
     EXPECT_GE(tooLarge, junkDataWithLargeSize.max_size());
 
     EXPECT_NO_THROW(handler.addNewBinaryStore(BinaryStore::createFromConfig(