clang-format: really avoid return type alone on line

Should fix some instances of very long lines doing the
following:

    void
    fn( ...really long parameter list... )

.clang-format

@@ -55,3 +55,4 @@ SpacesInConditionalStatement: false
 SpacesInContainerLiterals: false
 SpacesInParentheses: false
 SpacesInSquareBrackets: false
+PenaltyReturnTypeOnItsOwnLine: 1000