tipc: Fix bug in topology server byte swapping routine

This patch fixes TIPC's topology server so that it does byte swapping
correctly when endianness conversion is required.  (Note: This bug only
impacted an application if it issues a subscription request to a
topology server on another node, rather than the server on it's own
node; since the topology server is normally not accessible by off-node
applications, most TIPC applications were not impacted by the bug.)

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>