LU-15026 zfs: Fix ZFS(2.0.0-1) build error on CentOS (3.10)

LU-15026 zfs: Fix ZFS(2.0.0-1) build error on CentOS (3.10)

ZFS: (2.0.0-1)
Lustre: 608cce73d51 LU-15007 tests: quota enable cmd fix
CentOS: 3.10.0-1160.15.2.el7.x86_64

This patch fixes two build failures seens as below for
the above configuration

First
~~~~~
In file included from:
/root/zfs/zfs_git_lustre_build/zfs/include/sys/spa.h:39:0,
	from libmount_utils_zfs.c:32:
	/root/zfs/<path>/.../sys/zfs_context.h:110:27:
	fatal error: sys/byteorder.h: No such file or directory
	#include <sys/byteorder.h>

Second
~~~~~~
gcc -rdynamic -shared -export-dynamic -pthread \
	-L/root/zfs/zfs_git_lustre_build/zfs/lib/libzfs/.libs/
	-L/root/zfs/zfs_git_lustre_build/zfs/lib/libnvpair/.libs
	-o mount_osd_zfs.so \
	`ar -t libmount_utils_zfs.a` \
	-ldl -lzfs -lnvpair -lzpool
	/usr/bin/ld: cannot find -lzpool
	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
	collect2: error: ld returned 1 exit status

Test-Parameters: trivial fstype=zfs
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I5be8cc846da1ca213f1bd3c29b6b55acc22928f2
Reviewed-on: https://review.whamcloud.com/45016
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>