tipc: remove inline instances from C source files.

Untie gcc's hands and let it do what it wants within the
individual source files.  There are two files, node.c and
port.c -- only the latter effectively changes (gcc-4.5.2).
Objdump shows gcc deciding to not inline port_peernode().

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