Remove some redundant doc comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210118 91177308-0d34-0410-b5e6-96231b3b80d8
Update comment. This should have been part of r210062.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210119 91177308-0d34-0410-b5e6-96231b3b80d8