Revert "sighandler() should take 2 arguments"

This reverts commit 0bb89b6c59 in
favor of a cleaner implementation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2182

cmd/arcstat/arcstat.py

@@ -413,7 +413,7 @@ def calculate():
         v["l2bytes"] = d["l2_read_bytes"] / sint
 
 
-def sighandler(foo, bar):
+def sighandler():
     sys.exit(0)