xfs: fix quota detection in fuzz tests

xfs: fix quota detection in fuzz tests

With metadir, quota options persist until they are changed by mount
options.  Therefore, we can set the quota flags in MKFS_OPTIONS and
needn't supply them in MOUNT_OPTIONS.  Unfortunately, this means that we
cannot grep the MOUNT_OPTIONS anymore; we must mount the fs and run
src/feature to determine if quotas are enabled.

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