Fix cppcheck warning "buffer may not be null-terminated after call to strncpy()"

libnfc/drivers/acr122_pcsc.c

@@ -271,6 +271,7 @@ acr122_pcsc_open(const nfc_context *context, const nfc_connstring connstring)
       return NULL;
     }
     strncpy(fullconnstring, ncs[index], sizeof(nfc_connstring));
+    fullconnstring[sizeof(nfc_connstring) - 1] = '\0';
     free(ncs);
     connstring_decode_level = acr122_pcsc_connstring_decode(fullconnstring, &ndd);
     if (connstring_decode_level < 2) {

libnfc/drivers/acr122_usb.c

@@ -410,6 +410,7 @@ acr122_usb_get_usb_device_name(struct usb_device *dev, usb_dev_handle *udev, cha
       if ((acr122_usb_supported_devices[n].vendor_id == dev->descriptor.idVendor) &&
           (acr122_usb_supported_devices[n].product_id == dev->descriptor.idProduct)) {
         strncpy(buffer, acr122_usb_supported_devices[n].name, len);
+        buffer[len - 1] = '\0';
         return true;
       }
     }

libnfc/drivers/pn53x_usb.c

@@ -295,6 +295,7 @@ pn53x_usb_get_usb_device_name(struct usb_device *dev, usb_dev_handle *udev, char
       if ((pn53x_usb_supported_devices[n].vendor_id == dev->descriptor.idVendor) &&
           (pn53x_usb_supported_devices[n].product_id == dev->descriptor.idProduct)) {
         strncpy(buffer, pn53x_usb_supported_devices[n].name, len);
+        buffer[len - 1] = '\0';
         return true;
       }
     }

libnfc/nfc.c

@@ -226,6 +226,7 @@ nfc_open(nfc_context *context, const nfc_connstring connstring)
     }
   } else {
     strncpy(ncs, connstring, sizeof(nfc_connstring));
+    ncs[sizeof(nfc_connstring) - 1] = '\0';
   }
 
   // Search through the device list for an available device