[analyzer] Fix PR11282 - an assert in markAsSink

This is another fallout from the refactoring. We were
calling MarkAsSink on a cached out node.
(Fixes radar://10376675)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143516 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed