Igr: fix non-blocking mode for read end of process pipe

src/igr-tests/igr.h

@@ -99,7 +99,7 @@ public:
         if (fcntl(fds[0], F_SETFD, FD_CLOEXEC) != 0) {
             throw std::system_error(errno, std::generic_category(), "pipe_consume_buffer: fcntl");
         }
-        if (fcntl(fds[0], F_SETFL, O_ASYNC) != 0) {
+        if (fcntl(fds[0], F_SETFL, O_NONBLOCK) != 0) {
             throw std::system_error(errno, std::generic_category(), "pipe_consume_buffer: fcntl");
         }