tests/codegen.py: removing unecessary print statement

A huge amount of output(boilerplate code) is
printed to the console screen.
This is not critical to the test results.
Removing them should be harmless.

It causes issues in Yocto Project when we run
automated testing.
https://bugzilla.yoctoproject.org/show_bug.cgi?id=14170

Signed-off-by: Yi Fan Yu <yifan.yu@windriver.com>
10 jobs for remove_print in 22 minutes and 36 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Style Check
passed #1130300
check-todos

00:01:44

passed #1130299
style-check-diff

00:01:55

 
  Build
passed #1130303
cross-android_api21_arm64

00:01:10

passed #1130304
cross-android_api28_arm64

00:01:35

passed #1130305
cross-mingw64

00:01:37

passed #1130302
debian-stable-x86_64

00:02:10

passed #1130301
fedora-x86_64

00:08:22

passed #1130306
win32-ps
msys2-mingw32

00:07:36

passed #1130307
win32-ps
vs2017-x64

00:07:50

 
  Coverage
passed #1130308
coverage

00:01:54

76.2%