constify path_get/path_put and fs_struct.c stuff

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/internal.h b/fs/internal.h
index 2f6af7f..507141f 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -69,7 +69,7 @@
 /*
  * fs_struct.c
  */
-extern void chroot_fs_refs(struct path *, struct path *);
+extern void chroot_fs_refs(const struct path *, const struct path *);
 
 /*
  * file_table.c