net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules

These files are non modular, but need to export symbols using
the macros now living in export.h -- call out the include so
that things won't break when we remove the implicit presence
of module.h from everywhere.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index fb545ed..af8ee7b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -26,6 +26,7 @@
 
 #include <linux/capability.h>
 #include <linux/errno.h>
+#include <linux/export.h>
 #include <linux/types.h>
 #include <linux/times.h>
 #include <linux/socket.h>