Fix StringExtractor.h issues.

Summary:
Fix StringExtractor.h issues.

* source/Plugins/Process/MacOSX-Kernel/ProcessKDP.cpp
  (#include "Utility/StringExtractor.h): Not needed, this is already
    included by ProcessKDP.h

* unittests/Utility/StringExtractorTest.cpp
  (#include "Utility/StringExtractor.h): Update include path to the
    new location.

Reviewers: labath, clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D10995

llvm-svn: 241596