RDS: Export symbols from core RDS

Now that rdma and tcp transports will be modularized,
we need to export a number of functions so they can call them.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/page.c b/net/rds/page.c
index c460743..55c21ef 100644
--- a/net/rds/page.c
+++ b/net/rds/page.c
@@ -81,6 +81,7 @@
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(rds_page_copy_user);
 
 /*
  * Message allocation uses this to build up regions of a message.