[analyzer] Fix a bug in region store that lead to undefined value false
positives.

The includeSuffix was only set on the first iteration through the
function, resulting in invalid regions being produced by getLazyBinding
(ex: zoomRegion.y).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174016 91177308-0d34-0410-b5e6-96231b3b80d8