Fixed a few warnings from hpvm rt controller

llvm/projects/hpvm-tensor-rt/tensor_runtime/include/hpvm-rt-controller.h

@@ -137,7 +137,7 @@ void RuntimeController::readConfigurationFile(const char *str) {
   bool readingFirstLine = false;
 
   for (std::string line; std::getline(qin, line); ) {
-    DEBUG("line: ", line, "\n");
+    DEBUG("line: ", line.c_str(), "\n");
 
     // Tokenize using ' ' as delimiter
     // Vector to store tokens
@@ -147,7 +147,7 @@ void RuntimeController::readConfigurationFile(const char *str) {
       tokens.push_back(i);
 
     for (unsigned i = 0; i < tokens.size(); i++ )
-      DEBUG("t: ", tokens[i], "\n");
+      DEBUG("t: ", tokens[i].c_str(), "\n");
 
     DEBUG("\n");