Fix a typo of variable name in install.cpp

    }

    // Check for downgrade version.

    int64_t build_timestampt = property_get_int64(

    int64_t build_timestamp = property_get_int64(

            "ro.build.date.utc", std::numeric_limits<int64_t>::max());

    int64_t pkg_post_timespampt = 0;

    int64_t pkg_post_timestamp = 0;

    // We allow to full update to the same version we are running, in case there

    // is a problem with the current copy of that version.

    if (metadata["post-timestamp"].empty() ||

        !android::base::ParseInt(metadata["post-timestamp"].c_str(),

                                 &pkg_post_timespampt) ||

        pkg_post_timespampt < build_timestampt) {

                                 &pkg_post_timestamp) ||

        pkg_post_timestamp < build_timestamp) {

        if (metadata["ota-downgrade"] != "yes") {

            LOG(ERROR) << "Update package is older than the current build, expected a build "

                       "newer than timestamp " << build_timestampt << " but package has "

                       "timestamp " << pkg_post_timespampt << " and downgrade not allowed.";

                       "newer than timestamp " << build_timestamp << " but package has "

                       "timestamp " << pkg_post_timestamp << " and downgrade not allowed.";

            return INSTALL_ERROR;

        }

        if (pkg_pre_build_fingerprint.empty()) {