Fix string module use

tools/plotting/bar_chart.py

@@ -20,7 +20,6 @@ a generic histogram builder based on gnuplot backend
 anton nekrutenko | anton@bx.psu.edu
 """
 
-import string
 import sys
 import tempfile
 
@@ -43,7 +42,7 @@ def main(tmpFileName):
     try:
         in_file = open(sys.argv[1], 'r')
         xtic = int(sys.argv[2])
-        col_list = string.split(sys.argv[3], ",")
+        col_list = sys.argv[3].split(",")
         title = 'set title "' + sys.argv[4] + '"'
         ylabel = 'set ylabel "' + sys.argv[5] + '"'
         ymin = sys.argv[6]