fix: zero initialize local variables. (#1743)

* Zero initialize local variables.

* Initialize xmpID_

samples/write-test.cpp

@@ -58,7 +58,7 @@ int main(int argc, char* const argv[])
 
     std::string testFile = argv[1];
     std::istringstream iss(argv[2]);
-    int testNo;
+    int testNo = 0;
     iss >> testNo;
 
     int rc = 0;