util: Update & fix bug in m5stats2streamline.py

1) writeBinary function binary_list can have either string or ints and it needs to be properly converted to bytes
2) packed32(x) function can have x as int or float. Incase of float it needs to be converted to int
3) encode lines to string using .decode() or else TypeError will be invoked during run

Change-Id: I678169f191901f02a80187418a17adbc1240c7d3

util/streamline/m5stats2streamline.py

@@ -668,7 +668,7 @@ def parseProcessInfo(task_file):
     task_name_failure_warned = False
 
     for line in process_file:
-        match = re.match(process_re, line.decode("ISO-8859-1"))
+        match = re.match(process_re, line.decode())
         if match:
             tick = int(match.group(1))
             if start_tick < 0: