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/ipx/ipx_proc.c b/net/ipx/ipx_proc.c
index 26b5bfc..f8ba30d 100644
--- a/net/ipx/ipx_proc.c
+++ b/net/ipx/ipx_proc.c
@@ -9,6 +9,7 @@
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
 #include <linux/seq_file.h>
+#include <linux/export.h>
 #include <net/net_namespace.h>
 #include <net/tcp_states.h>
 #include <net/ipx.h>