[analyzer] Scan the correct store when finding symbols in a LazyCompoundVal.

Previously, we were scanning the current store. Now, we properly scan the
store that the LazyCompoundVal came from, which may have very different
live symbols.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175232 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed