docs: fix ext4 documentation table formatting problems

It turns out that the latex table formatters lay out table columns with
the exact proportional widths given in the table metadata, even if text
overflows outside the box.  This was not caught during the initial
import because the HTML renderers are smart enough to fudge the table.

Fix the table column width formatting problems in the data structures
and algorithms documentation so that we don't have squashed columns.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>