[TCP]: TCP acts like it is always out of memory.

[TCP]: TCP acts like it is always out of memory.

Current 2.6.7 tree acts as if it is alway under memory pressure because
a recent change did a s/tcp_memory_pressure/tcp_prot.memory_pressure/.
The problem is tcp_prot.memory_pressure is a pointer, so it is always non-zero!

Rather than using *tcp_prot.memory_pressure, just go back to looking at
tcp_memory_pressure.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@redhat.com>