tipc: fix link name length check

In commit 4f07b80c ("tipc: check msg->req data len in
tipc_nl_compat_bearer_disable") the same patch code was copied into
routines: tipc_nl_compat_bearer_disable(),
tipc_nl_compat_link_stat_dump() and tipc_nl_compat_link_reset_stats().
The two link routine occurrences should have been modified to check
the maximum link name length and not bearer name length.

Fixes: 4f07b80c

 ("tipc: check msg->reg data len in tipc_nl_compat_bearer_disable")
Signed-off-by: John Rutherford <john.rutherford@dektech.com.au>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>