Modify TestHelp to search for LLDB-Info.plist in the correct place

This is required to run the test suite outside of the source tree
or on a case sensitive file system.

llvm-svn: 133460
diff --git a/lldb/test/help/TestHelp.py b/lldb/test/help/TestHelp.py
index 77142e1..999fa40 100644
--- a/lldb/test/help/TestHelp.py
+++ b/lldb/test/help/TestHelp.py
@@ -20,7 +20,7 @@
 
     def version_number_string(self):
         """Helper function to find the version number string of lldb."""
-        plist = os.path.join(os.getcwd(), os.pardir, os.pardir, "resources", "LLDB-info.plist")
+        plist = os.path.join(os.environ["LLDB_SRC"], "resources", "LLDB-Info.plist")
         try:
             CFBundleVersionSegFound = False
             with open(plist, 'r') as f: