[IPV4]: Consolidate common SNMP code

This patch moves the SNMP code shared between IPv4/IPv6 from proc.c
into net/ipv4/af_inet.c.  This makes sense because these functions
aren't specific to /proc.

As a result we can again skip proc.o if /proc is disabled.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 3bd25f5..4ff6c15 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -10,11 +10,11 @@
 	     tcp_minisocks.o tcp_cong.o \
 	     datagram.o raw.o udp.o udplite.o \
 	     arp.o icmp.o devinet.o af_inet.o  igmp.o \
-	     sysctl_net_ipv4.o fib_frontend.o fib_semantics.o \
-	     proc.o
+	     sysctl_net_ipv4.o fib_frontend.o fib_semantics.o
 
 obj-$(CONFIG_IP_FIB_HASH) += fib_hash.o
 obj-$(CONFIG_IP_FIB_TRIE) += fib_trie.o
+obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_IP_MULTIPLE_TABLES) += fib_rules.o
 obj-$(CONFIG_IP_MROUTE) += ipmr.o
 obj-$(CONFIG_NET_IPIP) += ipip.o