generic/709,710: rework these for exchangerange vs. quota testing

generic/709,710: rework these for exchangerange vs. quota testing

The exchange-range implementation is now completely separate from the
old swapext ioctl, so let's migrate these quota tests to exchangerange.

There's no point in maintaining these tests for the legacy swapext code
because it returns EINVAL if any quota is enabled and the two files have
different user/group/project ids.  Originally I had forward ported the
old swapext ioctl to use commitrange as its backend, but that will be
dropped in favor of porting xfs_fsr to use commitrange directly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Zorro Lang <zlang@kernel.org>