ext4: remove useless ext4_pin_inode()

This function is never used from the beginning (and is commented out);
let's remove it.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/inode.c

@@ -6082,36 +6082,6 @@ void ext4_dirty_inode(struct inode *inode, int flags)
 	return;
 }
 
-#if 0
-/*
- * Bind an inode's backing buffer_head into this transaction, to prevent
- * it from being flushed to disk early.  Unlike
- * ext4_reserve_inode_write, this leaves behind no bh reference and
- * returns no iloc structure, so the caller needs to repeat the iloc
- * lookup to mark the inode dirty later.
- */
-static int ext4_pin_inode(handle_t *handle, struct inode *inode)
-{
-	struct ext4_iloc iloc;
-
-	int err = 0;
-	if (handle) {
-		err = ext4_get_inode_loc(inode, &iloc);
-		if (!err) {
-			BUFFER_TRACE(iloc.bh, "get_write_access");
-			err = jbd2_journal_get_write_access(handle, iloc.bh);
-			if (!err)
-				err = ext4_handle_dirty_metadata(handle,
-								 NULL,
-								 iloc.bh);
-			brelse(iloc.bh);
-		}
-	}
-	ext4_std_error(inode->i_sb, err);
-	return err;
-}
-#endif
-
 int ext4_change_inode_journal_flag(struct inode *inode, int val)
 {
 	journal_t *journal;