Update README.md

Author: Carl Chang

README.md

@@ -19,7 +19,7 @@ As one of my earliest Python projects, feel free to fork and make your own impro
 
 ### Sample Output
 ```
-sample@sample:~$ check_snmp.py -r 192.168.1.120
+sample@sample:~$ ./check_snmp.py -r 192.168.1.120
 Overall system status: critical (critical)
 Processor status: ok (ok)
 Memory status: ok (ok|ok)