[debuginfo-tests] Avoid "import commands" which was deprecated in Py3

llvm-svn: 346059
diff --git a/debuginfo-tests/lit.cfg.py b/debuginfo-tests/lit.cfg.py
index 6b47dd5..ac922c4 100644
--- a/debuginfo-tests/lit.cfg.py
+++ b/debuginfo-tests/lit.cfg.py
@@ -5,7 +5,6 @@
 import re
 import subprocess
 import tempfile
-import commands
 
 import lit.formats
 import lit.util
@@ -64,6 +63,7 @@
 lit.util.usePlatformSdkOnDarwin(config, lit_config)
 
 if platform.system() == 'Darwin':
+    import commands
     xcode_lldb_vers = commands.getoutput("xcrun lldb --version")
     match = re.search('lldb-(\d+)', xcode_lldb_vers)
     if match: