Use Python 3.x compatible syntax constructs

Avoid print operator, deprected except and
other things covered by statical checks.

Change-Id: I89f9608b977b2d4567300ec82558284dac347c9a
diff --git a/tools/find_stack_traces.py b/tools/find_stack_traces.py
index 3129484..0ce1500 100755
--- a/tools/find_stack_traces.py
+++ b/tools/find_stack_traces.py
@@ -110,7 +110,7 @@
 
 
 def usage():
-    print """
+    print("""
 Usage: find_stack_traces.py <logurl>
 
 Hunts for stack traces in a devstack run. Must provide it a base log url
@@ -118,20 +118,20 @@
 
 Returns a report listing stack traces out of the various files where
 they are found.
-"""
+""")
     sys.exit(0)
 
 
 def print_stats(items, fname, verbose=False):
     errors = len(filter(lambda x: x.level == "ERROR", items))
     traces = len(filter(lambda x: x.level == "TRACE", items))
-    print "%d ERRORS found in %s" % (errors, fname)
-    print "%d TRACES found in %s" % (traces, fname)
+    print("%d ERRORS found in %s" % (errors, fname))
+    print("%d TRACES found in %s" % (traces, fname))
 
     if verbose:
         for item in items:
-            print item
-        print "\n\n"
+            print(item)
+        print("\n\n")
 
 
 def main():