Attempt to fix failing watchpoints for debian os buildbot.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@181447 91177308-0d34-0410-b5e6-96231b3b80d8
Fix assertion from previous fix for debian os watchpoints.

Also mark one of the tests as expected fail on Linux due to the debian fix.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@181448 91177308-0d34-0410-b5e6-96231b3b80d8