netfilter: nf_nat_sip: fix mangling

In (b20ab9c netfilter: nf_ct_helper: better logging for dropped packets)
there were some missing brackets around the logging information, thus
always returning drop.

Closes https://bugzilla.kernel.org/show_bug.cgi?id=60061

Signed-off-by: Balazs Peter Odor <balazs@obiserver.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_nat_sip.c

@@ -230,9 +230,10 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff,
 					&ct->tuplehash[!dir].tuple.src.u3,
 					false);
 			if (!mangle_packet(skb, protoff, dataoff, dptr, datalen,
-					   poff, plen, buffer, buflen))
+					   poff, plen, buffer, buflen)) {
 				nf_ct_helper_log(skb, ct, "cannot mangle received");
 				return NF_DROP;
+			}
 		}
 
 		/* The rport= parameter (RFC 3581) contains the port number