fs/9p: Prevent multiple inclusion of same header

Add necessary #ifndef #endif blocks to avoid mulitple inclusion of same headers

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/fid.h b/fs/9p/fid.h
index c058f1c..bb0b6e7 100644
--- a/fs/9p/fid.h
+++ b/fs/9p/fid.h
@@ -19,7 +19,8 @@
  *  Boston, MA  02111-1301  USA
  *
  */
-
+#ifndef FS_9P_FID_H
+#define FS_9P_FID_H
 #include <linux/list.h>
 
 /**
@@ -46,3 +47,4 @@
 struct p9_fid *v9fs_fid_clone(struct dentry *dentry);
 int v9fs_fid_add(struct dentry *dentry, struct p9_fid *fid);
 struct p9_fid *v9fs_writeback_fid(struct dentry *dentry);
+#endif