extract_programmer_param() stores allocated memory in param, so make
sure it is freed at the end of the function.

Change-Id: I363e66b49c1ed4034ac058b94a938c8bb197e048
Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Found-by: Coverity CID 1403823
Reviewed-on: https://review.coreboot.org/c/flashrom/+/34847


Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>