nfs: return NFSERR_IO is we detect broken file on tape

currently we return NFSERR_LAYOUTTRYLATER and client
tries later. Stop infinite loop as we cant get file
anyway.

Acked-by: Gerd Behrmann
Acked-by: Paul Millar
Target: master
Require-book: no
Require-notes: no
(cherry picked from commit ef2091a9130cc0206e2534685b34ea5d6abe5590)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Merge pull request #465 from kofemann/stop-on-broken-tape-2.7

nfs: return NFSERR_IO is we detect broken file on tape