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 email@example.com