LU-16664 build: Debian server fails building crypto.c

LU-16664 build: Debian server fails building crypto.c

When building deb files against a server built without
CONFIG_FS_ENCRYPTION it still attempts to build crypto.c
when it should not.

Test-Parameters: trivial
Fixes: 068e5f13fb ("LU-13743 build: Explicitly require encryption support")
Signed-off-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Change-Id: Id1e67daa7b021fdfee49be4eb0beb2b86ca62c39
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50406
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: xinliang <xinliang.liu@linaro.org>
Reviewed-by: jsimmons <jsimmons@infradead.org>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>