[TCP]: Fix tcp_mem[] initialization.

Change tcp_mem initialization function.  The fraction of total memory
is now a continuous function of memory size, and independent of page
size.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/ipv4/tcp.c
Simple merge