netfilter: nf_flow_table: rename nf_flow_table.c to nf_flow_table_core.c

Preparation for adding more code to the same module
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/Makefile

@@ -111,6 +111,8 @@ obj-$(CONFIG_NFT_FWD_NETDEV)	+= nft_fwd_netdev.o
 
 # flow table infrastructure
 obj-$(CONFIG_NF_FLOW_TABLE)	+= nf_flow_table.o
+nf_flow_table-objs := nf_flow_table_core.o
+
 obj-$(CONFIG_NF_FLOW_TABLE_INET) += nf_flow_table_inet.o
 
 # generic X tables