Mostly these are bugprone-unused-local-non-trivial-variable.
Also fix instances of:
- bugprone-optional-value-conversion
- bugprone-inc-dec-in-conditions (please check this loop is correct, it
is the only non trivial code change in here)
- bugprone-unused-return-value (well, by fixing the lint config)
There are three notable changes relating to undefined vars:
- openLogFile ignoring the result. This is because openLogFile does a
whole bunch of mutation of member variables
- hiliteMatches: i am guessing this is because showing the derivation
name was unhelpful and it just got changed
- canonPath in NarAccessor: canonPath inside of a thing that is supposed
to be vfs based cannot possibly be correct, so let's delete it given
it is unused.
Fixes: https://git.lix.systems/lix-project/lix/issues/584
Change-Id: I887adc9ff28b61f726dcfed197e6796b414c2fcf
