xfs/216: always disable rmap and reflink when creating log size test fs

xfs/216: always disable rmap and reflink when creating log size test fs

This test seems to check that log sizes scale up properly with the size
of the filesystem, given a carefully controlled set of mkfs parameters.
Since turning on reflink or rmap will change the minimum log size,
change the test to detect their presence and ensure they're disabled.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Tested-by: Yang Xu<xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>