Fixup TestLinuxCore on windows

test_same_pid_running couldn't delete the temporary files, while we had them open. Deleting the
target should make things work.

llvm-svn: 265529

lldb/packages/Python/lldbsuite/test/functionalities/postmortem/linux-core/TestLinuxCore.py

@@ -92,3 +92,5 @@ class LinuxCoreTestCase(TestBase):
             self.assertEqual(frame.GetLineEntry().GetLine(),
                     line_number("main.c", "Frame " + backtrace[i]))
             self.assertEqual(frame.FindVariable("F").GetValueAsUnsigned(), ord(backtrace[i][0]))
+
+        self.dbg.DeleteTarget(target)