final search through complete buffer

Description:
The current implementation of the _puts_PF tests in the DwarfOS/tests/src/_stdio.c file compares from the buffer index, which may lead to inaccurate results if the buffer index is corrupted due to erroneous behavior. To ensure the accuracy and reliability of the tests, it is crucial to modify the comparison to start from the beginning of the buffer.

User Story:
As a developer, I expect the _puts_PF tests to compare from the beginning of the buffer, so that I can ensure the accuracy and reliability of the tests