NFSD: restore EINVAL error translation in nfsd_commit()

NFSD: restore EINVAL error translation in nfsd_commit()

commit 86f03100de344b60910a2fa94e443e41dc5a8221 upstream.

commit f9f4af0131e9 ("nfsd: Replace use of rwsem with errseq_t")
incidentally broke translation of -EINVAL to nfserr_notsupp.
The patch restores that.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: f9f4af0131e9 ("nfsd: Replace use of rwsem with errseq_t")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>