sighandler() should take 2 arguments

Stopping arcstat.py with ^C always ends up with error:
TypeError: sighandler() takes no arguments (2 given)

Since no special signal handling was done in sighandler(),
it's simpler to just set SIGINT handler to SIG_DFL, which
terminates the script.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Isaac Huang <he.huang@intel.com>
Closes #2179

cmd/arcstat/arcstat.py

@@ -51,7 +51,7 @@ import re
 import copy
 
 from decimal import Decimal
-from signal import signal, SIGINT
+from signal import signal, SIGINT, SIG_DFL
 
 cols = {
     # HDR:        [Size, Scale, Description]
@@ -413,10 +413,6 @@ def calculate():
         v["l2bytes"] = d["l2_read_bytes"] / sint
 
 
-def sighandler():
-    sys.exit(0)
-
-
 def main():
     global sint
     global count
@@ -429,7 +425,7 @@ def main():
     if count > 0:
         count_flag = 1
 
-    signal(SIGINT, sighandler)
+    signal(SIGINT, SIG_DFL)
     while True:
         if i == 0:
             print_header()