set proper migration status on ->write error (v5)

If ->write fails, declare migration status as MIG_STATE_ERROR.

Also, in buffered_file.c, ->close the object in case of an
error.

Fixes "migrate -d "exec:dd of=file", where dd fails to open file.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

buffered_file.c

@@ -230,8 +230,10 @@ static void buffered_rate_tick(void *opaque)
 {
     QEMUFileBuffered *s = opaque;
 
-    if (s->has_error)
+    if (s->has_error) {
+        buffered_close(s);
         return;
+    }
 
     qemu_mod_timer(s->timer, qemu_get_clock(rt_clock) + 100);
 

migration.c

@@ -316,8 +316,14 @@ ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
     if (ret == -1)
         ret = -(s->get_error(s));
 
-    if (ret == -EAGAIN)
+    if (ret == -EAGAIN) {
         qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
+    } else if (ret < 0) {
+        if (s->mon) {
+            monitor_resume(s->mon);
+        }
+        s->state = MIG_STATE_ERROR;
+    }
 
     return ret;
 }