test_printf intermittently fails on Windows10

test_printf intermittently fails on Windows10.
We have verified that device side printf is working correctly and driver is handling the same as expected.
The problem is narrowed down to the way test handles redirection of printf on host. The other printf tests which directly print on command-line or to a file are working fine.
This looks like a test issue where we need to fix the re-direction of printf.

Start with the test_printf implementation and compare its host printf redirection with the other printf tests that write to the command line or a file. Done means the test no longer intermittently fails on Windows 10 while device-side printf and driver behavior remain unchanged.

Written by the indexing model from the issue text.