[DLM] zero unused parts of sockaddr_storage

When we build a sockaddr_storage for an IP address, clear the unused parts as
they could be used for node comparisons.

I have seen this occasionally make sctp connections fail.
Signed-Off-By: NPatrick Caulfield <pcaulfie@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/dlm/lowcomms.c

@@ -313,6 +313,7 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
 		in6_addr->sin6_port = cpu_to_be16(port);
 		*addr_len = sizeof(struct sockaddr_in6);
 	}
+	memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
 }
 
 /* Close a remote connection and tidy up */