bridge: depends on INET

br_multicast calls ip_send_check(), so it should depend on INET.

built-in:
br_multicast.c:(.text+0x88cf4): undefined reference to `ip_send_check'

or modular:
ERROR: "ip_send_check" [net/bridge/bridge.ko] undefined!

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>