cmd_sign/rwsig: Free sign_option.prikey in the main function

It's better to free it in the same function as it was allocated.

BRANCH=none
BUG=none
TEST=make runtests

Change-Id: I7a224364c4b1afce5a274b944d32fc1b7ba5db30
Reviewed-on: https://chromium-review.googlesource.com/446177
Commit-Ready: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
2 files changed