[clang-tidy] Fix handling of parens around new expressions in make_<smartptr> checks.

Summary:
Extra parentheses around a new expression result in incorrect code
after applying fixes.

Reviewers: hokein

Reviewed By: hokein

Subscribers: xazax.hun, cfe-commits

Differential Revision: https://reviews.llvm.org/D52989

llvm-svn: 344058