slirp: clarify license of slirp files using SPDX: explicit BSD

Add SPDX license identifier to clarify the license of files with
explicit 3-clause BSD license header.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/ip.h b/src/ip.h
index bef6918..e5d4aa8 100644
--- a/src/ip.h
+++ b/src/ip.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
 /*
  * Copyright (c) 1982, 1986, 1993
  *	The Regents of the University of California.  All rights reserved.