ext2_{set_link,delete_entry}(): don't bother with page_addr

ext2_set_link() simply doesn't use it anymore and ext2_delete_entry()
can easily obtain it from the directory entry pointer...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Tested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>