[NETFILTER]: Fix timeout sysctls on big-endian 64bit architectures

The connection tracking timeout variables are unsigned long, but
proc_dointvec_jiffies is used with sizeof(unsigned int) in the sysctl
tables. Since there is no proc_doulongvec_jiffies function, change the
timeout variables to unsigned int.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>