ipvs: Add proper dependencies on IP_VS, and fix description header line.

Linus noted a build failure case:

net/netfilter/ipvs/ip_vs_xmit.c: In function 'ip_vs_tunnel_xmit':
net/netfilter/ipvs/ip_vs_xmit.c:616: error: implicit declaration of function 'ip_select_ident'

The proper include file (net/ip.h) is being included in ip_vs_xmit.c to get
that declaration.  So the only possible case where this can happen is if
CONFIG_INET is not enabled.

This seems to be purely a missing dependency in the ipvs/Kconfig file IP_VS
entry.

Also, while we're here, remove the out of date "EXPERIMENTAL" string in the
IP_VS config help header line.  IP_VS no longer depends upon CONFIG_EXPERIMENTAL
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/ipvs/Kconfig

@@ -2,8 +2,8 @@
 # IP Virtual Server configuration
 #
 menuconfig IP_VS
-	tristate "IP virtual server support (EXPERIMENTAL)"
-	depends on NETFILTER
+	tristate "IP virtual server support"
+	depends on NET && INET && NETFILTER
 	---help---
 	  IP Virtual Server support will let you build a high-performance
 	  virtual server based on cluster of two or more real servers. This