linux-aio: Fix typo in read() EINTR check

Signed-off-by: NStefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

linux-aio.c

@@ -123,7 +123,7 @@ static void qemu_laio_completion_cb(void *opaque)
 
         do {
             ret = read(s->efd, &val, sizeof(val));
-        } while (ret == 1 && errno == EINTR);
+        } while (ret == -1 && errno == EINTR);
 
         if (ret == -1 && errno == EAGAIN)
             break;