tests: avoid executing dirname(1) command

Bash parameter expansion does the same thing.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
tools: add usage information to checkconfig.sh

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
docs: make hexdump.1 color specification easier to understand

Fix also spacing, input line lenghts, and troff table for data that is a
table.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
tests: align last.1 with recent phantom detection

None existing account is not still-logged-in but gone mysteriously,
assuming wtmp logout markup is missing.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
swaplabel: wrong version number in check

$ swaplabel /dev/sda2
swaplabel: /dev/sda2: unsupported swap version '1'

The mkswap does not allow any other version, so swaplabel(8) must be
wrong.

Reference: https://github.com/karelzak/util-linux/blob/master/disk-utils/mkswap.c#L520
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
isosize: move file name printing after error determination

Earlier the filename printing was buffered, and exit at error made output
to appear in front of prompt.  Output below demonstrates the brokenness.

prompt> isosize /etc /
isosize: /etc: might not be an ISO filesystem
isosize: read error on /etc: Is a directory
/etc: prompt>

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
tests: add isosize --sectors and --divisor tests

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
isosize: make --divisor to require argument

Silly bug, only the short option -d allowed divisor argument.

Signed-off-by: Sami Kerola <kerolasa@iki.fi>
tests: update ionice test

Signed-off-by: Karel Zak <kzak@redhat.com>