Fix comparison signed unsigned warning.

test/unit/Common/utHash.cpp

@@ -52,5 +52,5 @@ class utHash : public ::testing::Test {
 TEST_F( utHash, SuperFastHashTest ) {
     const char *Data = "-21416115v";
     auto result = SuperFastHash(Data, 10);
-    EXPECT_NE(0, result);
+    EXPECT_NE(0u, result);
 }