[XFS] Map EFSCORRUPTED to an actual error code, not just a made up one

(990).	Turns out some ye-olde unices used EUCLEAN as
Filesystem-needs-cleaning, so now we use that too.

SGI-PV: 953954
SGI-Modid: xfs-linux-melb:xfs-kern:26286a

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