These values are set in main() from user input. Ensure
they are cleared out first.
Clears a static analysis warning:
warning: The right operand of '*' is a garbage value
1000.0 * rc->layer_target_bitrate[0] / rc->layer_framerate[0];
Change-Id: I09bd209be5aff31b87597a24d37a9673fa99381b