Fix unused variable warnings:

This patch fixes warnings during a release build:

  mlir/lib/Dialect/Transform/IR/TransformInterfaces.cpp:198:52: error:
  lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]

  bolt/lib/Rewrite/RewriteInstance.cpp:5318:18: error: unused variable
  'HasNoAddress' [-Werror,-Wunused-variable]