NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 3d0f513..dcc7633 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -578,6 +578,13 @@
 		set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 }
 
+static inline void
+pnfs_copy_range(struct pnfs_layout_range *dst,
+		const struct pnfs_layout_range *src)
+{
+	memcpy(dst, src, sizeof(*dst));
+}
+
 extern unsigned int layoutstats_timer;
 
 #ifdef NFS_DEBUG