[clang-format] Use SpacesBeforeTrailingComments for "option" directive
AnnotatingParser::next() is needed to implicitly set TT_BlockComment
versus TT_LineComment. On most other paths through
AnnotatingParser::parseLine(), all tokens are consumed to achieve that.
This change updates one place where this wasn't done.
Contributed by @dchai!
Reviewed By: krasimir
Differential Revision: https://reviews.llvm.org/D60541