tipc: Delete useless function prototypes

Removes several function declarations that aren't used anywhere,
either because they reference routines that no longer exist or
because all users of the function reference it after it has already
been defined.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>