EX-7683 utils: always try to use our own lz4/lz4hc

EX-7683 utils: always try to use our own lz4/lz4hc

lz4/lz4hc provided by the kernel do not grok a compression level.
The built-in lz4/lz4hc do, so always build them as dedicated kernel
modules llz4.ko and llz4hc.ko, with the same .cra_name but with a
slightly higher .cra_priority = 110, so that they are preferred over
the in-kernel modules if any.

And try to manually load the llz4/llz4hc kernel modules when a file
requires compression with the corresponding alg. This is a "one-shot"
try that allows us to prefer our modules that has level support, but
continues to at least compress/decompress files even if our own
modules are not available.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I0bdf267f998e21df81e460250a653aed34e3215d
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51474
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>