[SROA] Adjust to new clang-format style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202134 91177308-0d34-0410-b5e6-96231b3b80d8
[SROA] Simplify some of the logic to dig out the old pointer value by
using OldPtr more heavily. Lots of this code was written before the
rewriter had an OldPtr member setup ahead of time. There are already
asserts in place that should ensure this doesn't change any
functionality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202135 91177308-0d34-0410-b5e6-96231b3b80d8