text ematch: check for NULL pointer before destroying textsearch config

While validating the configuration em_ops is already set, thus the
individual destroy functions are called, but the ematch data has
not been allocated and associated with the ematch yet.

Signed-off-by: Thomas Graf <tgraf@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/em_text.c b/net/sched/em_text.c
index 7632532..ea8f566 100644
--- a/net/sched/em_text.c
+++ b/net/sched/em_text.c
@@ -103,7 +103,8 @@
 
 static void em_text_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
 {
-	textsearch_destroy(EM_TEXT_PRIV(m)->config);
+	if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config)
+		textsearch_destroy(EM_TEXT_PRIV(m)->config);
 }
 
 static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)