Accepts relative paths to trace output directory

Change-Id: I87b9fc63d97f5f39fd46800f1da33c44f7ff7eb0
diff --git a/tools/run_benchmark.py b/tools/run_benchmark.py
index cef162e..120d1bf 100755
--- a/tools/run_benchmark.py
+++ b/tools/run_benchmark.py
@@ -125,6 +125,9 @@
     if options.output:
         options.output = os.path.abspath(options.output)
 
+    if options.dump_trace_to_directory:
+        options.dump_trace_to_directory = os.path.abspath(options.dump_trace_to_directory)
+
     if options.temp:
         temp = options.temp
         os.makedirs(temp, exist_ok=True)