Since commit v3.7.0-rc1~348^2~3 (FindBISON: Change usage of [VERBOSE
<file>] to [VERBOSE [<file>]], 2016-07-16) we always list the VERBOSE
output file as an output of our custom command even if the option is not
used.  This causes the rule to re-run every time (e.g. with Ninja).
Revert one hunk from that change (that looks incorrect) to fix it.

Closes: #16426