net_buf: do not assert on buffer reset when flags are set

There is only one flag, NET_BUF_EXTERNAL_DATA, used when net_buf was
allocated with external data. The flag is checked in net_buf_clone() and
net_buf_destroy(). net_buf with external buffer can be used for
receiving and transmitting. net_buf_reset() is convenient way
to reset net_buf with external data before it is re-enqueued again.

Signed-off-by: Johann Fischer <[email protected]>

Author: jfischer-no

lib/net_buf/buf.c

@@ -87,7 +87,6 @@ static inline struct net_buf *pool_get_uninit(struct net_buf_pool *pool,
 
 void net_buf_reset(struct net_buf *buf)
 {
-	__ASSERT_NO_MSG(buf->flags == 0U);
 	__ASSERT_NO_MSG(buf->frags == NULL);
 
 	net_buf_simple_reset(&buf->b);