robot-results-parser: get input file from cmd args

Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
diff --git a/robot-results-parser.py b/robot-results-parser.py
index 7219cee..af394f8 100755
--- a/robot-results-parser.py
+++ b/robot-results-parser.py
@@ -20,8 +20,11 @@
 #
 # Author: Naresh Kamboju <naresh.kamboju@linaro.org>
 
+import sys
 import xml.etree.ElementTree as ET
-tree = ET.parse('/tmp/output.xml')
+
+input_file = sys.argv[1]
+tree = ET.parse(input_file)
 root = tree.getroot()
 
 for statistics in root.findall('statistics'):