To build ip_vs as a module sysctl_rmem_max and sysctl_wmem_max
needs to be exported.

The dependency was added by "ipvs: wakeup master thread" patch.
Signed-off-by: NHans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>