xfstests: filter spaces in xfs_quota output in test case 108

xfstests: filter spaces in xfs_quota output in test case 108

xfs_quota can output different amounts of spaces when it is trying to align
its output. This can cause output mismatch on several systems in test case 108.

Filter all the consecutive spaces in xfs_quota output to just one space,
making the test case independent of the alignment.

Signed-off-by: Boris Ranto <branto@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>