ceph: make several helper accessors take const pointers

None of these helper functions change anything in memory, so we can
declare their arguments as const.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/super.h

@@ -407,22 +407,26 @@ struct ceph_inode_info {
 	struct inode vfs_inode; /* at end */
 };
 
-static inline struct ceph_inode_info *ceph_inode(struct inode *inode)
+static inline struct ceph_inode_info *
+ceph_inode(const struct inode *inode)
 {
 	return container_of(inode, struct ceph_inode_info, vfs_inode);
 }
 
-static inline struct ceph_fs_client *ceph_inode_to_client(struct inode *inode)
+static inline struct ceph_fs_client *
+ceph_inode_to_client(const struct inode *inode)
 {
 	return (struct ceph_fs_client *)inode->i_sb->s_fs_info;
 }
 
-static inline struct ceph_fs_client *ceph_sb_to_client(struct super_block *sb)
+static inline struct ceph_fs_client *
+ceph_sb_to_client(const struct super_block *sb)
 {
 	return (struct ceph_fs_client *)sb->s_fs_info;
 }
 
-static inline struct ceph_vino ceph_vino(struct inode *inode)
+static inline struct ceph_vino
+ceph_vino(const struct inode *inode)
 {
 	return ceph_inode(inode)->i_vino;
 }