Remove extraneous parentheses.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@204986 91177308-0d34-0410-b5e6-96231b3b80d8
Replace nested switches with if.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@204987 91177308-0d34-0410-b5e6-96231b3b80d8