tipc: simplify trivial boolean return

Checking and returning 'true' boolean is useless as it will be
returning at end of function

Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>