reorder calls to prevent a crash

Signed-off-by: Steve Markgraf <steve@steve-m.de>

src/rtl-sdr.c

@@ -813,11 +813,11 @@ int rtlsdr_close(rtlsdr_dev_t *dev)
 
 	rtlsdr_deinit_baseband(dev);
 
+	_rtlsdr_free_async_buffers(dev);
+
 	libusb_release_interface(dev->devh, 0);
 	libusb_close(dev->devh);
 
-	_rtlsdr_free_async_buffers(dev);
-
 	libusb_exit(dev->ctx);
 
 	free(dev);