examples/unix/ffi_example.py: Remove TODO, make output more clear.

examples/unix/ffi_example.py

@@ -18,8 +18,8 @@ print()
 
 perror("ffi before error")
 open("somethingnonexistent__", 0)
-print(errno)
-print(errno.get())
+print("errno object:", errno)
+print("errno value:", errno.get())
 perror("ffi after error")
 print()
 
@@ -32,8 +32,7 @@ def cmp(pa, pb):
 cmp_c = ffi.callback("i", cmp, "pp")
 print("callback:", cmp_c)
 
-# TODO: violates Py semantics, pass bytearray
-s = "foobar"
+s = bytearray(b"foobar")
 print("org string:", s)
 qsort(s, len(s), 1, cmp_c)
-print("qsort'ed:", s)
+print("qsort'ed string:", s)