tutorial: add missing return in hello_world example

diff --git a/docs/tutorial_bcc_python_developer.md b/docs/tutorial_bcc_python_developer.md
index 338c43c..e26dcff 100644 (file)
--- a/docs/tutorial_bcc_python_developer.md
+++ b/docs/tutorial_bcc_python_developer.md
@@ -23,7 +23,7 @@ Here's the code for hello_world.py:
 
 ```Python
 from bcc import BPF
-BPF(text='int kprobe__sys_clone(void *ctx) { bpf_trace_printk("Hello, World!\\n"); }').trace_print()
+BPF(text='int kprobe__sys_clone(void *ctx) { bpf_trace_printk("Hello, World!\\n"); return 0; }').trace_print()
 ```
 
 There are six things to learn from this: