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>

net/sctp/socket.c

@@ -78,6 +78,7 @@
 #include <net/inet_common.h>
 
 #include <linux/socket.h> /* for sa_family_t */
+#include <linux/export.h>
 #include <net/sock.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>