Remove redundant check for nullptr.
Remove redundant check for nullptr.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@298866 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 91a21c4db6409d2b6c4d0b8e57ec1dfa73451663)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm