Fix bug in clang-format's vim integration cause by r186789.

After the first operation, the buffer contents has changed and thus all
other operations would be invalid. Executing the operations in reversed
order should fix this.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186840 91177308-0d34-0410-b5e6-96231b3b80d8