[XFS] Tight loop in xfs_finish_reclaim_all prevented the xfslogd to run

its queue of IO completion callbacks, thus creating the deadlock between
umount and xfslogd. Breaking the loop solves the problem.

SGI-PV: 943821
SGI-Modid: xfs-linux-melb:xfs-kern:202363a

Signed-off-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>