Fixup device/vendor node handling

Currently we readout the data as string only to convert it to hex. In
the error case, we leak the fd for the given nodes.

Read the data as hex directly, error out if that fails and avoid the
leaks.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

src/overlay.cpp

@@ -595,29 +595,29 @@ void init_gpu_stats(uint32_t& vendorID, uint32_t reported_deviceID, overlay_para
 
          SPDLOG_DEBUG("amdgpu path check: {}/device/vendor", path);
          FILE *fp;
-         char str[10];
          string device = path + "/device/device";
          if ((fp = fopen(device.c_str(), "r"))){
-            fscanf(fp, "%s", str);
-            uint32_t temp = strtol(str, NULL, 16);
+            uint32_t temp = 0;
+            if (fscanf(fp, "%x", &temp) == 1) {
             // if (temp != reported_deviceID && deviceID != 0){
+            //    fclose(fp);
             //    SPDLOG_DEBUG("DeviceID does not match vulkan report {}", reported_deviceID);
             //    continue;
             // }
-            deviceID = temp;
+               deviceID = temp;
+            }
             fclose(fp);
          }
          string vendor = path + "/device/vendor";
          if ((fp = fopen(vendor.c_str(), "r"))){
-            fscanf(fp, "%s", str);
-            uint32_t temp = strtol(str, NULL, 16);
-            if (temp != vendorID)
+            uint32_t temp = 0;
+            if (fscanf(fp, "%x", &temp) != 1 || temp != vendorID) {
+               fclose(fp);
                continue;
+            }
             fclose(fp);
          }
-         string line = str;
-         trim(line);
-         if (line != "0x1002" || !file_exists(path + "/device/gpu_busy_percent"))
+         if (deviceID != 0x1002 || !file_exists(path + "/device/gpu_busy_percent"))
             continue;
 
          if (pci_bus_parsed && pci_dev) {