unix_diag: Write it into kbuild

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/unix/Makefile

@@ -6,3 +6,6 @@ obj-$(CONFIG_UNIX)	+= unix.o
 
 unix-y			:= af_unix.o garbage.o
 unix-$(CONFIG_SYSCTL)	+= sysctl_net_unix.o
+
+obj-$(CONFIG_UNIX_DIAG)	+= unix_diag.o
+unix_diag-y		:= diag.o