[Format] Fix a warning

This patch fixes:

  clang/unittests/Format/TokenAnnotatorTest.cpp:2181:29: error: lambda
  capture 'Style' is not used [-Werror,-Wunused-lambda-capture]

Author: kazutakahirata

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -2178,7 +2178,7 @@ TEST_F(TokenAnnotatorTest, UnderstandTableGenTokens) {
 
   TestLexer Lexer(Allocator, Buffers, Style);
   AdditionalKeywords Keywords(Lexer.IdentTable);
-  auto Annotate = [&Lexer, &Style](llvm::StringRef Code) {
+  auto Annotate = [&Lexer](llvm::StringRef Code) {
     return Lexer.annotate(Code);
   };