BUG/MEDIUM: connection: fix pool free regression with recent ppv2 TLV patches

In commit fecc573 ("MEDIUM: connection: Generic, list-based allocation
and look-up of PPv2 TLVs") there was a tiny mistake, elements of length
<= 128 are allocated from pool_pp_128 but only those of length < 128 are
released to this pool, other ones go to pool_pp_256. Because of this,
elements of size exactly 128 are allocated from 128 and released to 256.
It can be reproduced a few times by running sample_fetches/tlvs.vtc 1000
times with -DDEBUG_DONT_SHARE_POOLS -DDEBUG_MEMORY_POOLS -DDEBUG_EXPR
-DDEBUG_STRICT=2 -DDEBUG_POOL_INTEGRITY -DDEBUG_POOL_TRACING
-DDEBUG_NO_POOLS. Not sure why it doesn't reproduce more often though.

No backport is needed. This should address github issues haproxy#2275 and haproxy#2274.

Author: wtarreau

src/connection.c

@@ -569,7 +569,7 @@ void conn_free(struct connection *conn)
 		LIST_DELETE(&tlv->list);
 		if (tlv->len > HA_PP2_TLV_VALUE_256)
 			free(tlv);
-		else if (tlv->len < HA_PP2_TLV_VALUE_128)
+		else if (tlv->len <= HA_PP2_TLV_VALUE_128)
 			pool_free(pool_head_pp_tlv_128, tlv);
 		else
 			pool_free(pool_head_pp_tlv_256, tlv);