xfs_repair: continue after xfs_bunmapi deadlock avoidance

xfs_repair: continue after xfs_bunmapi deadlock avoidance

xfs_bunmapi can legitimately return before all work is done, to
avoid deadlocks across AGs.

Sadly nobody told xfs_repair, so it fires an assert if this happens:

 phase6.c:1410: longform_dir2_rebuild: Assertion `done' failed.

Fix this by calling back in until all work is done, as we do
in the kernel.

Fixes: 5a8bcc ("xfs: fix multi-AG deadlock in xfs_bunmapi")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1641116
Reported-by: Tomasz Torcz <tomek@pipebreaker.pl>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>