With -N, an operand naming a directory under /proc/sys failed with
"Is a directory". Recursively list the variable names below it instead,
in directory order, without opening the variable files.
Keep the existing behavior for operands beginning with / or . and for
directory operands used without -N.
With -N, a variable with a multi-line value printed its name once per
line. Print the name once instead, matching procps-ng. This also covers
--names and -N -n.
procps-ng rejects -N together with -q when key operands are present.
uutils accepted the combination and printed the names.
Reject it while processing key operands, leaving the -a forms and the
no-operand behavior unchanged. Use util_name() in the diagnostic so a
renamed binary prints its own name.
vmstat -D labeled the number of I/Os currently in progress as
"in progress IO". procps-ng prints "inprogress IO". Update the label
and make test_disk_sum check it.
Sichen