nfsd: Fix typo "accesible"

[ Upstream commit 34a62493 ]

Trivial fix.

Cc: linux-nfs@vger.kernel.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>