checksrc: find bad indentation in conditions without open brace

checksrc: find bad indentation in conditions without open brace

If the previous line starts with if/while/for AND ends with a closed
parenthesis and there's an equal number of open and closed parentheses
on that line, verify that this line is indented $indent more steps, if
not a cpp line.

Also adjust the fall-out from this fix.

Closes #11054