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

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/linux-aio.c b/linux-aio.c
index 5e892b0..68f4b3d 100644
--- a/linux-aio.c
+++ b/linux-aio.c
@@ -123,7 +123,7 @@
 
         do {
             ret = read(s->efd, &val, sizeof(val));
-        } while (ret == 1 && errno == EINTR);
+        } while (ret == -1 && errno == EINTR);
 
         if (ret == -1 && errno == EAGAIN)
             break;