utils: iio_rwdev: fix cancelling streaming

If we try to cancel the utility with a signal, we'll cancel the buffer (at
least on linux) which means we'll likely fail to dequeue a block if we
are waiting for one. On top of that the flag 'app_running' is set to false
which means that the loop condition '(ret && app_running)' is false and
so we do not leave it. This all means that we'll proceed with an
invalid block leading to a segfault.

Hence, always break the loop if iio_stream_get_next_block() fails (which
was the previous behavior) but only log it if the application is
running.

Signed-off-by: Nuno Sá <[email protected]>

utils/iio_rwdev.c

@@ -459,8 +459,9 @@ int main(int argc, char **argv)
 
 		block = iio_stream_get_next_block(stream);
 		ret = iio_err(block);
-		if (ret && app_running) {
-			dev_perror(dev, ret, "Unable to get next block");
+		if (ret) {
+			if (app_running)
+				dev_perror(dev, ret, "Unable to get next block");
 			break;
 		}