Fix low verbosity levels in htools

In a few cases, we tested the verbosity level for (== 0), instead of
higher/lower than a certain value. If the user passes multiple
"--quiet" options, this can result in negative verbosity levels, which
behave like "extra verbosity".

Sigh for plain data types as opposed to proper verbosity levels…

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>