[Tooling] Remove redundant check, NFCi

Summary: The Database check looks redundant.

Reviewers: bkramer

Subscribers: klimek, cfe-commits

Differential Revision: https://reviews.llvm.org/D32909

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@302236 91177308-0d34-0410-b5e6-96231b3b80d8