infiniband: add in export.h for files using EXPORT_SYMBOL/THIS_MODULE

These were getting it implicitly via device.h --> module.h but
we are going to stop that when we clean up the headers.

Fix these in advance so the tree remains biscect-clean.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_fs.c b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
index 86eae22..a3dcf45 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_fs.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
@@ -37,6 +37,7 @@
 struct file_operations;
 
 #include <linux/debugfs.h>
+#include <linux/export.h>
 
 #include "ipoib.h"