[linux-lvm] lvcreate and lvremove --quiet option is not quiet

[Alasdair G Kergon]

The simple problem is that the code today does not distinguish between
essential output (to stdout) and incidental output (to stdout).

If I run 'pvs' I expect a list of PVs.
If I run 'pvs --quiet' do I still expect to see that list?

Today, there is no distinction: pvs output and the message you're wanting
to suppress are the same category of message.

The fix is to introduce a new macro alongside log_print so we can distinguish
between the two cases, then have --quiet discard the incidental output and
review every instance of log_print to see if it needs moving into the 'discard
if quiet' category.  Also provide an lvm.conf option to make --quiet the default
for those who want that.  etc.

Alasdair