Removing should_flash_in_userspace check

This check isn't needed as super_flash_helper.cpp calls a different
should_flash_in_userspace that isn't reliant on $ANDROID_PRODUCT_OUT
being set. Current code will fail when calling fastboot update

Test: fastboot update update.zip without calling lunch
Bug: 283330320
Change-Id: Icefe6092befb747b7f419ea997e0834602808d69