constify path_get/path_put and fs_struct.c stuff

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index dc984fe..961bc12 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -451,7 +451,7 @@
  *
  * Given a path increment the reference count to the dentry and the vfsmount.
  */
-void path_get(struct path *path)
+void path_get(const struct path *path)
 {
 	mntget(path->mnt);
 	dget(path->dentry);
@@ -464,7 +464,7 @@
  *
  * Given a path decrement the reference count to the dentry and the vfsmount.
  */
-void path_put(struct path *path)
+void path_put(const struct path *path)
 {
 	dput(path->dentry);
 	mntput(path->mnt);