LU-13673 misc: quiet compiler warning on armv7l

LU-13673 misc: quiet compiler warning on armv7l

Add AM_CFLAGS when building lfs.c and lfs_project.c.

Avoid overflow in jobid_get_from_environ() and lu_prandom_u64_max().

Quiet printk() warning for mismatched type of size_t variables
by using %z modifier for those variables.

Fixes: 742897a967cf ("LU-13274 uapi: make lnet UAPI headers C99 compliant")
Fixes: df21a3b9eb01 ("LU-12790 obdclass: print jobid error message properly")
Fixes: 645b72c5c058 ("LU-12495 obdclass: generate random u64 max correctly")
Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Ib424497d1543fd7840d630facf3210b6fa1344c7
Reviewed-on: https://review.whamcloud.com/38927
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>