savevm: make qemu_file_put_notify() return errors

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/savevm.c b/savevm.c
index dee6899..b080d37 100644
--- a/savevm.c
+++ b/savevm.c
@@ -523,9 +523,9 @@
     return ret;
 }
 
-void qemu_file_put_notify(QEMUFile *f)
+int qemu_file_put_notify(QEMUFile *f)
 {
-    f->put_buffer(f->opaque, NULL, 0, 0);
+    return f->put_buffer(f->opaque, NULL, 0, 0);
 }
 
 void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size)